REESE LIBRARY OF THI: UNIVERSITY OF CALIFORNIA. Received. L//U24&/ . J^ Accessions No. ^4 that the steam is returned to the air in the form of water, and C 34 WORKSHOP MANIPULATION. of the same volume as when it entered the boiler, there is a gain effected by avoiding atmospheric pressure, varying according to the perfection of the arrangements employed. Engines operated by means of hot air, called caloric engines, and engines operated by gas, or explosive substances, all act substantially upon the same general principles as steam-engines ; the greatest distinction being between those engines wherein the generation of heat is by the combustion of fuel, and those wherein heat and expansion are produced by chemical action. With the exception of a limited number of caloric or air engines, steam machinery comprises nearly all expansive engines that are employed at this day for motive-power ; and it may be safely assumed that a person who has mastered the general principles of steam-engines will find no trouble in analysing and under- standing any machinery acting from expansion due to heat, whether air, gas, or explosive agents be employed. This method of treating the subject of motive-engines will no doubt be presenting it in a new way, but it is merely beginning at an unusual place. A learner who commences with first prin- ciples, instead of pistons, valves, connections, and bearings, will find in the end that he has not only adopted the best course, but the shortest one to understand steam and other expansive ,(1.) What is principal among the details of steam machinery ? (2.) What has been the most important improvement recently made in steam machinery ? (3.) What has been the result of expansive engines generally stated ? (4.) Why has water proved the most successful among various expansive substances employed to develop power ? (5.) Why does a condensing engine develop more power than a non-con- densing one ? (6.) How far back from its development into power can heat be traced as an element in nature 1 (7.) Has the property of com- bustion a common source in all substances ? WATER-POWER. 35 CHAPTER VIII. WATER-POWER. WATER-WHEELS, next to steam-engines, are the most common motive agents. For centuries water-wheels remained without much improvement or change down to the period of turbine wheels, when it was discovered that instead of being a very simple matter, the science of hydraulics and water-wheels involved some very intricate conditions, giving rise to many problems of scientific interest, that in the end have produced the class known as turbine wheels. A modern turbine water-wheel, one of the best construction, operating under favourable conditions, gives a percentage of the power of the water which, after deducting the friction of the wheel, almost reaches the theoretical coefficient or equals the gravity of the water; it may therefore be assumed that there will in the future be but little improvement made in such water-wheels except in the way of simplifying and cheapening their construction. There is, in fact, no other class of machines which seem to have reached the same state of improvement as water-wheels, nor any other class of machinery that is con- structed with as much uniformity of design and arrangement, in different countries, and by different makers. Water-wheels, or water-power, as a mechanical subject, is apparently quite disconnected with shop manipulation, but will serve as an example for conveying general ideas of force and motion, and, on these grounds, will warrant a more extended notice than the seeming connection with the general subject calls for. In the remarks upon steam-engines it was explained that power is derived from heat, and that the water and the engine were both to be regarded as agents through which power was applied, and further, that power is always a product of heat. There is, perhaps, no problem in the whole range of mechanics more interesting than to trace the application of this principle in machinery ; one that is not only interesting but instructive, and may suggest to the mind of an apprentice a course of 36 WORKSHOP MANIPULATION. investigation that will apply to many other matters connected with power and mechanics. Power derived from water by means of wheels is due to the gravity of the water in descending from a higher to a lower level ; but the question arises, What has heat to do with this 1 If heat is the source of power, and power a product of heat, there must be a connection somewhere between heat and the descent of the water. Water, in descending from one level to another, can give out no more power than was consumed in raising it to the higher level, and this power employed to raise the water is found to be heat. Water is evaporated by heat of the sun, expanded until it is lighter than the atmosphere, rises through the air, and by condensation falls in the form of rain over the earth's surface; then drains into the ocean through streams and rivers, to again resume its round by another course of evaporation, giving out in its descent power that we turn to useful account by means of water- wheels. This principle of evaporation is continually going on ; the fall of rain is likewise quite constant, so that streams are maintained within a sufficient regularity to be available for operating machinery. The analogy between steam-power and water-power is there- fore quite complete. Water is in both cases the medium through which power is obtained; evaporation is also the leading principle in both, the main difference being that in the case of steam-power the force employed is directly from the expansion of water by heat, and in water-power the force is an indirect result of expansion of water by heat. Every one remembers the classification of water-wheels met with in the older school-books on natural philosophy, where we are informed that there are three kinds of wheels, as there were "three kinds of levers" namely, overshot, undershot, and breast wheels with a brief notice of Barker's mill, which ran apparently without any sufficient cause for doing so. Without finding fault with the plan of describing water-power commonly adopted in elementary books, farther than to say that some explana- tion of the principles by which power is derived from the water would have been more useful, I will venture upon a different classification of water-wheels, more in accord with modern practice, but without reference to the special mechanism of the different wheels, except when unavoidable. Water-wheels can be divided into four general types. WATER-POWER. 37 First. Gravity wheels, acting directly from the weight of the water which is loaded upon a wheel revolving in a vertical plane, the weight resting upon the descending side until the water has reached the lowest point, where it is discharged. Second. Impact wheels, driven by the force of spouting water that expends its percussive force or momentum against the vanes tangental to the course of rotation, and at a right angle to the face of the vanes or floats. Third. Reaction wheels, that are "enclosed," as it is termed, and filled with water, which is allowed to escape under pressure through tangental orifices, the .propelling force being derived from the unbalanced pressure within the wheel, or from the re- action due to the weight and force of the water thrown off from the periphery. Fourth. Pressure wheels, acting in every respect upon the principle of a rotary steam-engine, except in the differences that arise from operating with an elastic and a non-elastic fluid ; thk pressure of the water resting continually against the vanes and "abutment," without means of escape except by the rotation of the wheel. To this classification may be added combinationUwhe^fej/'' acting partly by the gravity and partly by the percussiaktfhrce "& f of the water, by impact combined with reaction, or by nW!$5^ and maintained pressure. Gravity, or "overshot" wheels, as they are called, for some reasons will seem to be the most effective, and capable of utilis- ing the whole effect due to the gravity of the water ; but in practice this is not the case, and it is only under peculiar con- ditions that wheels of this class are preferable to turbine wheels, and in no case will they give out a greater per cent, of power than turbine wheels of the best class. The reasons for this will be apparent by examining the conditions of their operation. A gravity wheel must have a diameter equal to the fall of water, or, to use the technical name, the height of the head. The speed at the periphery of the wheel cannot well exceed sixteen feet per second without losing a part of the effect by the wheel anticipating or overrunning the water. This, from the large diameter of the wheels, produces a very slow axial speed, and a train of multiplying gearing becomes necessary in order to reach the speed required in most operations where power is 33 WORKSHOP MANIPULATION. applied. This train of gearing, besides being liable to wear and accident, and costing usually a large amount as an investment, consumes a considerable part of the power by frictional resist- ance, especially when such gearing consists of tooth wheels. Gravity wheels, from their large size and their necessarily ex- posed situation, are subject to be frozen up in cold climates ; and as the parts are liable to be first wet and then dry, or warm and cold by exposure to the air and the water alternately, the tendency to corrosion if constructed of iron, or to decay if of wood, is much greater than in submerged wheels. Gravity wheels, to realise the highest measure of effect from the water, require a diameter so great that they must drag in the water at the bottom or delivering side, and are for this reason especially affected by back-water, to which all wheels are more or less liable from the reflux of tides or by freshets. These disadvan- tages are among the most notable pertaining to gravity wheels, and have, with other reasons such as the inconvenience of con- struction, greater cost, and so on driven such wheels out of use by the force of circumstances, rather than by actual tests or theoretical deductions. Impact wheels, or those driven by the percussive force of water, including the class termed turbine water-wheels, are at this time generally employed for heads of all heights. The general theory of their action may be explained in the following propositions : 1. The spouting force of water is theoretically equal to its gravity. 2. The percussive force of spouting water can be fully utilised if its motion is altogether arrested by the vanes of a wheel. 3. The force of the water is greatest by its striking against planes at right angles to its course. 4. Any force resulting from water rebounding from the vanes parallel to their face, or at any angle not reverse to the motion of the wheel, is lost. 5. This rebounding action becomes less as the columns of water projected upon the wheel are increased in number and diminished in size. 6. To meet the conditions of rotation in the wheel, and to facilitate the escape of the water without dragging, after it has expended its force upon the vanes, the reversed curves of the turbine is the best-known arrangement. WATER-POWER. 39 It is, of course, very difficult to deal with so complex a subject as the present one with words alone, and the reader is recom- mended to examine drawings, or, what is better, water-wheels themselves, keeping the above propositions in view. Modern turbine wheels have been the subject of the most careful investigation by able engineers, and there is no lack of mathematical data to be referred to and studied after the general principles are understood. The subject, as said, is one of great complicity if followed to detail, and perhaps less useful to a mechanical engineer who does not intend to confine his practice to water-wheels, than other subjects that may be studied with greater advantage. The subject of water-wheels may, indeed, be called an exhausted one that can promise but little return for labour spent upon it with a view to improvements, at least. The efforts of the ablest hydraulic engineers have not added much to the percentage of useful effect realised by turbine wheels during many years past. Keaction wheels are employed to a limited extent only, and will soon, no doubt, be extinct as a class of water-wheels. In speaking of reaction wheels, I will select what is called Barker's mill for an example, because of the familiarity with which it is known, although its construction is greatly at variance with modern reaction wheels. There is a problem as to the principle of action in a Barker wheel, which although it may be very clear in a scientific sense, remains a puzzle to the minds of many who are well versed in mechanics, some contending that the power is directly from pressure, others that it is from the dynamic effect due to reaction. It is one of the problems so difficult to determine by ordinary standards, that it serves as a matter of endless debate between those who hold different views ; and considering the advantage usually derived from such controversies, perhaps the best manner of disposing of the problem here is to state the two sides as clearly as possible, and leave the reader to determine for himself which he thinks right. Presuming the vertical shaft and the horizontal arms of a Barker wheel to be filled with water under a head of sixteen feet, there would be a pressure of about seven pounds upon each superficial inch of surface within the cross arm, exerting an equal force in every direction. By opening an orifice at the sides of these arms equal to one inch of area, the pressure would at that 40 WORKSHOP MANIPULATION. point be relieved by the escape of the water, and the internal pressure be unbalanced to that extent. In other words, opposite this orifice, and on the other side of the arm, there would be a force of seven pounds, which being unbalanced, acts as a pro- pelling power to drive the wheel. This is one theory of the principle upon which the Barker wheel operates, which has been laid down in Vogdes' " Mensura- tion," and perhaps elsewhere. The other theory alluded to is that, direct action and reaction being equal, ponderable matter discharged tangentally from the periphery of a wheel must create a reactive force equal to the direct force with which the weight is thrown off. To state it more plainly, the spouting water that issues from the arm of a Barker wheel must react in the opposite course in proportion to its weight. The two propositions may be consistent with each other er even identical, but there still remains an apparent difference. The latter seems a plausible theory, and perhaps a correct one ; but there are two facts in connection with the operation of reaction water-wheels which seem to controvert the latter and favour the first theory, namely, that reaction wheels in actual practice seldom utilise more than forty per cent, of useful effect from the water, and that their speed may exceed the initial velocity of the water. With this the subject is left as one for argument or investigation on the part of the reader. Pressure wheels, like gravity wheels, should, from theoretical inference, be expected to give a high per cent, of power. The water resting with the whole of its weight against the vanes or abutments, and without chance of escape except by turning the wheel, seems to meet the conditions of realising the whole effect due to the gravity of the water, and such wheels would no doubt be economical if they had not to contend with certain mechanical difficulties that render them impracticable in most cases. A pressure wheel, like a steam-engine, must include running contact between water-tight surfaces, and like a rotary steam- engine, this contact is between surfaces which move at different rates of speed in the same joint, so that the wear is unequal, and increases as the speed or the distance from the axis. When it is considered that the most careful workmanship has never produced rotary engines that would surmount these diffi- culties in working steam, it can hardly be expected they can be overcome in using water, which is not only liable to be filled WIND-POWER. 41 with grit and sediment, but lacks the peculiar lubricating pro- perties of steam. A rotary steam-engine is in effect the same as a pressure water-wheel, and the apprentice in studying one will fully understand the principles of the other. (1.) What analogy may be found between steam and water power 1 ? (2.) What is the derivation of the name turbine ? (3.) To what class of water-wheels is this name applicable 1 (4.) How may water-wheels be classified? (5.) Upon what principle does a reaction water-wheel operate ? (6.) Can ponderable weight and pressure be independently considered in the case? (7.) Why cannot radial running joints be maintained in machines ? (8.) Describe the mechanism in common use for sustaining the weight of turbine wheels, and the thrust of propeller shafts. CHAPTER IX, WIND-POWER. WIND-POWER, aside from the objections of uncertainty and irreg- ularity, is the cheapest kind of motive-power. Steam machinery, besides costing a large sum as an investment, is continually deteriorating in value, consumes fuel, and requires continual skilled attention. Water-power also requires a large investment, greater in many cases than steam-power, and in many places the plant is in danger of destruction by freshets. Wind-power is less expensive in every way, but is unreliable for constancy except in certain localities, and these, as it happens, are for the most part distant from other elements of manufacturing industry. The operation of wind- wheels is so simple and so generally under- stood that no reference to mechanism need be made here. The force of the wind, moving in right lines, is easily applied to producing rotary motion, the difference from water-power being mainly in the comparative weakness of wind currents and the greater area required in the vanes upon which the wind acts. Turbine wind-wheels have been constructed on very much the same plan as turbine water-wheels. In speaking of wind-power, the propositions about heat must not be forgotten. It has been ex- plained how heat is almost directly utilised by the steam-engine, 42 WORKSHOP MANIPULATION. and how the effect of heat is utilised by water-wheels in a less direct manner, and the same connection will be found between heat and wind-wheels or wind-power. Currents of air are due to changes of temperature, and the connection between the heat that produces such air currents and their application as power is no more intricate than in the case of water-power. (1.) What is the difference in general between wind and water wheels 1 (2.) Can the course of wind, like that of water, be diverted and applied at pleasure ? (3.) On what principle does wind act against the vanes of a wheel ? (4.) How may an analogy between wind-power and heat be traced 1 CHAPTER X. MACHINERY FOR TRANSMITTING AND DISTRIBUTING POWER. To construe the term ''transmission of power" in its full sense, it will, when applied to machinery, include nearly all that has motion ; for with the exception of the last movers, or where power passes off and is expended upon work that is performed, all machinery of whatever kind may be called machinery of transmission. Custom has, however, confined the use of the term to such devices as are employed to convey power from one place to another, without including organised machines through which power is directly applied to the performance of work. Power is transmitted by means of shafts, belts, friction wheels, gearing, and in some cases by water or air, as various conditions of the work to be performed may require. Sometimes such machinery is employed as the conditions do not require, because there is, perhaps, nothing of equal importance connected with mechanical engineering of which there exists a greater diversity of opinion, or in which there is a greater diversity of practice, than in devices for transmitting power. I do not refer to questions of mechanical construction, although the remark might be true if applied in this sense, but to the kind of devices that may be best employed in certain cases. TRANSMITTING MACHINERY. 43 It is not proposed at tins time to treat of the construction of machinery for transmitting power, but to examine into the con- ditions that should determine which of the several plans of transmitting is best in certain cases whether belts, gearing, or shafts should be employed, and to note the principles upon which they operate. Existing examples do not furnish data as to the advantages of the different plans for transmitting power, because a given duty may be successfully performed by belts, gearing, or shafts even by water, air, or steam and the com- parative advantages of different means of transmission is not always an easy matter to determine. Machinery of transmission being generally a part of the fixed plant of an establishment, experiments cannot be made to insti- tute comparisons, as in the case of machines ; besides, there are special or local considerations such as noise, danger, freezing, and distance to be taken into account, which prevent any rules of general application. Yet in every case it may be assumed that some particular plan of transmitting power is better than any other, and that plan can best be determined by studying, first, the principles of different kinds of mechanism and its adaptation to the special conditions that exist ; and secondly, precedents or examples. A leading principle in machinery of transmission that more than- any other furnishes data for strength and proper propor- tions is, that the stress upon the machinery, whatever it may be, is inverse as the speed at which it moves. For example, a belt two inches wide, moving one thousand feet a minute, will theoretically perform the same work that one ten inches wide will do, moving at a speed of two hundred feet a minute ; or a shaft making two hundred revolutions a minute will transmit four times as much power as a shaft making but fifty revolu- tions in the same time, the torsional strain being the same in both cases. This proposition argues the expediency of reducing the pro- portions of mill gearing and increasing its speed, a change which has gradually been going on for fifty years past ; but there are opposing conditions which make a limit in this direction, such as the speed at which bearing surfaces may run, centrifugal strain, jar, and vibration. The object is to fix upon a point between what high speed, light weight, cheapness of cost suggest, and what the conditions of practical use and endurance demand. 44 WORKSHOP MANIPULATION. (1.) "What does the term "machinery of transmission" include, as applied in common use 1 (2.) Why cannot direct comparisons be made "between shafts, belts, and gearing? (3.) Define the relation between speed and strain in machinery of transmission. (4.) What are the principal conditions which limit the speed of shafts ? CHAPTER XL SHAFTS FOR TRANSMITTING POWER. THERE is no use in entering upon detailed explanations of what a learner has before him. Shafts are seen wherever there is machinery ; it is easy to see the extent to which they are employed to transmit power, and the usual manner of arranging them. Various text-books afford data for determining the amount of torsional strain that shafts of a given diameter will bear ; explain that their capacity to resist torsional strain is as the cube of the diameter, and that the deflection from transverse strains is so many degrees ; with many other matters that are highly useful and proper to know. I will therefore not devote any space to these things here, but notice some of the more obscure conditions that pertain to shafts, such as are demonstrated by practical experience rather than deduced from mathematical data. What is said will apply especially to what is called line-shafting for conveying and distributing power in machine-shops and other manufacturing establishments. The following propositions in reference to shafts will assist in under- standing what is to follow : 1. The strength of shafts is governed by their size and the arrangement of their supports. 2. The capacity of shafts is governed by their strength and the speed at which they run taken together. 3. The strains to which shafts are subjected are the torsional strain of transmission, transverse strain from belts and wheels, and strains from accidents, such as the winding of belts. 4. The speed at which shafts should run is governed by their size, the nature of the machinery to be driven, and the kind of bearings in which they are supported. 5. As the strength of shafts is determined by their size, and SHAFTS FOR TRANSMITTING POWER. 45 their size fixed by ike strains to which they are subjected, strains are first to be considered. There were three kinds of strain mentioned torsional, deflec- tive, and accidental. To meet these several strains the same means have to be provided, which is a sufficient size and strength to resist them hence it is useless to consider each of these dif- ferent strains separately. If we know which of the three is greatest, and provide for that, the rest, of course, may be dis- regarded. This, in practice, is found to be accidental strains to which shafts are in ordinary use subjected, and they are usually made, in point of strength, far in excess of any standard that would be fixed by either torsional or transverse strain due to the regular duty performed. This brings us back to the old proposition, that for structures which do not involve motion, mathematical data will furnish dimensions ; but the same rule will not apply in machinery. To follow the proportions for shafts that would be furnished by pure mathematical data would in nearly all cases lead to error. Experience has demonstrated that for ordinary cases, where power is transmitted and applied with tolerable regularity, a shaft three inches in diameter, making one hundred and fifty revolutions a minute, its bearings three to four diameters in length, and placed ten feet apart, will safely transmit fifty horse- power. By assuming this or any other well-proved example, and estimat- ing larger or smaller shafts by keeping their diameters as the cube root of the power to be transmitted, the distance between bearings as the diameter, and the speed inverse as the diameter, the reader will find his calculations to agree approximately with the modern practice of our best engineers. This is not men- tioned to give proportions for shafts, so much as to call atten- tion to accidental strains, such as winding belts, and to call attention to a marked discrepancy between actual practice and such proportions as would be given by what has been called the measured or determinable strains to which shafts are subjected. As a means for transmitting power, shafts afford the very important advantage that power can be easily taken off at any point throughout their length, by means of pulleys or gear- ing, also in forming a positive connection between the motive- power and machines, or between the different parts of machines. 46 WORKSHOP MANIPULATION, The capacity of shafts in resisting torsional strain is as the cube of their diameter, and the amount of torsional deflection in shafts is as their length. The torsional capacity being based upon the diameter, often leads to the construction of what may be termed diminishing shafts, lines in which the diameter of the several sections are diminished as the distance from the driving power increases, and as the duty to be performed becomes less. This plan of arranging line shafting has been and is yet quite com- mon, but certainly was never arrived at by careful observation. Almost every plan of construction has both advantages and dis- advantages, and the best means of determining the excess of either, in any case, is to first arrive at all the conditions as near as possible, then form a " trial balance," putting the advantages on one side and the disadvantages on the other, and footing up the sums for comparison. Dealing with this matter of shafts of uniform diameter and shafts of varying diameter in this way, there may be found in favour of the latter plan a little saving of material and a slight reduction of friction as advantages. The saving of material relates only to first cost, because the expense of fitting is greater in constructing shafts when the diameters of the different pieces vary; the friction, considering that the same velocity throughout must be assumed, is scarcely worth estimating. For disadvantages there is, on the other hand, a want of uni- formity in fittings that prevents their interchange from one part of a line shaft to the other a matter of great importance, as such exchanges are frequently required. A line shaft, when constructed with pieces of varying diameter, is special machinery, adapted to some particular place or duty, and not a standard product that can be regularly manufactured as a staple article by machinists, and thus afforded at a low price. Pulleys, wheels, bearings, and couplings have all to be specially pre- pared; and in case of a change, or the extension of lines of shafting, cause annoyance, and frequently no little expense, which may all be avoided by having shafts of uniform diameter. The bearings, besides being of varied strength and proportions, are generally in such cases placed at irregular inter- vals, and the lengths of the different sections of the shaft are sometimes varied to suit their diameter. With line shafts of uniform diameter, everything pertaining to the shaft such as hangers, couplings, pulleys, and bearings is interchangeable ; the pulleys, wheels, bearings, or hangers can be placed at plea- SHAFTS FOR TRANSMITTING POWER. 47 sure, or changed from one part of the shaft to another, or from one part of the works to another, as occasion may require. The first cost of a line of shafting of uniform diameter, strong enough for a particular duty, is generally less than that of a shaft con- sisting of sections varying in size. This may at first strange, but a computation of the number of supports with the expense of special fitting, will in nearly all cases saving. Attention has been called to this case as one wherein t ditions of operation obviously furnish true data to govern arrangement of machinery, instead of the determinable strains which the parts are subjected, and as a good example of the importance of studying mechanical conditions from a practical and experimental point of view. If the general diameter of a shaft is based upon the exact amount of power to be transmitted, or if the diameter of a shaft at various parts is based upon the torsional stress that would be sustained at these points, such a shaft would not only fail to meet the conditions of practical use, but would cost more by attempting such an adaptation. The regular working strain to which shafts are subjected is inversely as the speed at which they run. This becomes a strong reason in favour of arranging shafts to run at a maximum speed, provided there was nothing more than first cost to consider ; but there are other and more important conditions to be taken into account, prin- cipal among which are the required rate of movement where power is taken off to machines, and the endurance of bearings. In the case of line shafting for manufactories, if the speed varies so much from that of the first movers on machines as to require one or more intermediate or counter shafts, the expense would be very great ; on the contrary, if countershafts can be avoided, there is a great saving of belts, bearings, machinery, and obstruction. The practical limit of speed for line shafts is in a great measure dependent upon the nature of the bearings, a subject that will be treated of in another place. (1.) What kind of strains are shafts subjected to ? (2.) What deter- mines the strength of shafts in resisting transverse strain ? (3.) Why are shafts often more convenient than belts for transmitting power 1 (4.) What is the difference between the strains to which shafts and belts are subjected ? (5.) What is gained by constructing a line shaft of sections diminishing in size from the first mover? (6.) What is gained by constructing line shafts of uniform diameter ? 48 WORKSHOP MANIPULATION. CHAPTER XII. BELTS FOR TRANSMITTING POWER. THE traction of belts upon pulleys, like that of locomotive wheels upon railways, being incapable of demonstration except by actual experience, for a long time hindered the introduction of belts as a means of transmitting motion and power except in cases when gearing or shafts could not be employed. Motion is named separately, because with many kinds of machinery that are driven at high speed such as wood machines the transmission of rapid movement must be considered as well as power, and in ordinary practice it is only by means of belts that such high speeds may be communicated from one shaft to another. The first principle to be pointed out in regard to belts, to distinguish them from shafts as a means of transmitting power, is that power is communicated by means of tensile instead of torsional strain, the power during transmission being repre- sented in the difference of tension between the driving and the slack side of belts. In the case of shafts, their length, or the distance to which they may be extended in transmitting power, is limited by torsional resistance ; and as belts are not liable to this condition, we may conclude that unless there are other difficulties to be contended with, belts are more suitable . than shafts for transmitting power throughout long distances. Belts suffer resistance from the air and from friction in the bear- ings of supporting pulleys, which are necessary in long horizontal belts ; with these exceptions they are capable of moving at a very high rate of speed, and transmitting power without appreci- able loss. Following this proposition into modern engineering examples, we find how practice has gradually conformed to what these properties in belts suggest. Wire and other ropes of small diameter, to avoid air friction, and allowed to droop in low curves to avoid too many supporting pulleys, are now in many cases employed for transmitting power through long distances, as at Schaffhausen, in Germany. This system has been very success- fully applied in some cases for distributing power in large manu- facturing establishments. Belts, among which are included all BELTS FOR TRANSMITTING POWER, 49 flexible bands, do not afford the same facilities for taking off power at different points as shafts, but have advantages in transmitting power to portable machinery, when power is to be taken off at movable points, as in the case of portable travel- ling cranes, machines, and so on. An interesting example in the use of belts for communicating power to movable machinery is furnished by the travelling cranes of Mr Ramsbottom, in the shops of the L. It is well for an apprentice to invent or demonstrate all that he can the more the better ; but as explained in a previous- '' place, what is attempted should be according to some system, and with a proper object. Time spent groping in the dark after something of which no definite conception has been formed, or for any object not to fill an ascertained want, is generally time lost. To demonstrate or invent, one should begin methodically, like a bricklayer builds a wall, as he mortars and sets each brick, so should an engineer qualify, by careful study, each piece or movement that is added to a mechanical structure, so that when done, the result may be useful and enduring. As remarked, every attempt to generate anything new in machinery should be commenced by ascertaining a want of im- provement. When such a want has been ascertained, attention should be directed first to the principles upon which such want or fault is to be remedied. Proper mechanism can then be sup- plied like the missing links in a chain. Propositions thus stated may fail to convey the meaning intended ; this systematic plan of inventing may be better explained by an example. Presuming the reader to remember what was said of steam hammers in another place, and to be familiar with the uses and general construction of such hammers, let it be supposed steam-hammers, with the ordinary automatic valve action, those that give an elastic or steam-cushioned blow, are well known. Suppose further that by analysing the blows given by hammers of this kind, it is demonstrated that dead blows, such as are given when a hammer comes to a full stop in striking, are more effectual in certain kinds of work, and that steam-hammers would be improved by operating on this dead-stroke principle. Such a proposition would constitute the first stage of an inven- tion by demonstrating a fault in existing hammers, and a want of certain functions which if added would make an improvement. Proceeding from these premises, the first thing should be to examine the action of existing valve gear, to determine where this want of the dead-stroke function can best be supplied, and to gain the aid of such suggestions as existing mechanism may offer, also to see how far the appliances in use may become a part of any new arrangement. By examining automatic hammers it will be found that their L ] 62 WORKSHOP MANIPULATION. valves are connected to the drop by means of links, producing coincident movement of the piston and valve, and that the move- ment of one is contingent upon and governed by the other. It will also be found that these connections or links are capable of extension, so as to alter the relative position of the piston and valve, thereby regulating the range of the blow, but that the movement of the two is reciprocal or in unison. Reasoning in- ductively, not discovering or inventing, it may be determined that to secure a stamp blow of a hammer-head, the valve must not open or admit steam beneath the piston until a blow is completed and the hammer has stopped. At this point will occur one of those mechanical problems which requires what may be called logical solution. The valve must be moved by the drop ; there is no other moving mechanism avail- able ; the valve and drop must besides be connected, to insure co- incident action, yet the valve requires to move when the drop is still. Proceeding inductively, it is clear that a third agent must be introduced, some part moved by the drop, which will in turn move the valve, but this intermediate agent so arranged that it may continue to move after the hammer-drop has stopped. This assumed, the scheme is complete, so far as the relative movement of the hammer-drop and the valve, but there must be some plan of giving motion to this added mechanism. In many examples there may be seen parts of machinery which continue in motion after the force which propels them has ceased to act ; cannon balls are thrown for miles, the impelling force acting for a few feet only ; a weaver's shuttle performs nearly its whole flight after the driver has stopped. In the present case, it is therefore evident that an independent or subsequent movement of the valves may be obtained by the momentum of some part set in motion during the descent of the hammer-head. To sum up, it is supposed to have been determined by induc- tive reasoning, coupled with some knowledge of mechanics, that a steam hammer, to give a dead blow, requires the following con- ditions in the valve gearing : 1. That the drop and valve, while they must act relatively, cannot move in the same time, or in direct unison. 2. The connection between the hammer drop and valve cannot be positive, but must be broken during the descent of the drop. 3. The valve must move after the hammer stops. 4. To cause a movement of the valve after the hammer stops INVENTION. 163 there must be an intermediate agent, that will continue to act after the movement of the hammer drop has ceased. 5. The obvious means of attaining this independent movement of the valve gear, is by the momentum of some part set in motion by the hammer-drop, or by the force of gravity reacting on this auxiliary agent. The invention is now complete, and as the principles are all within the scope of practical mechanism, there is nothing left to do but to devise such mechanical expedients as will carry out the principles laid down. This mechanical scheming is a second, and in some sense an independent part of machine improvement, and should always be subservient to principles ; in fact, to separate mechanical scheming from principles, generally constitutes what has been called chance invention. Referring again to the hammer problem, it will be found by examining the history that the makers of automatic-acting steam-hammers capable of giving the dead stamp blow, have employed the principle which has been described. Instead of employing the momentum, or the gravity of moving parts, to open the valve after the hammer stops, some engineers have depended upon disengaging valve gear by the concussion and jar of the blow, so that the valve gearing, or a portion of it, fell and opened the valve. The ' dead blow gear,' fitted to the earlier Nasmyth, or Wilson, hammers, was constructed on the latter plan, the valve spindle when disengaged being moved by a spring. I will not consume space to explain the converse of this system of inventing, nor attempt to describe how a chance schemer would proceed to hunt after mechanical expedients to accomplish the valve movement in the example given. Inventions in machine improvement, no matter what their nature, must of course consist in and conform to certain fixed modes of operating, and no plan of urging the truth of a pro- position is so common, even with a chance inventor, as to trace out the ' principles ' which govern his discovery. In studying improvements with a view to practical gain, a learner can have no reasonable hope of accomplishing much in fields already gone over by able engineers, nor in demonstrating anything new in what may be called exhausted subjects, such as steam-engines or water-wheels ; he should rather choose new and special subjects, but avoid schemes not in some degree confirmed by existing practice. 164 WORKSHOP MANIPULATION. It has been already remarked that the boldness of young engineers is very apt to be inversely as their experience, not to say their want of knowledge, and it is only by a strong and determined effort towards conservatism, that a true balance is maintained in judging of new schemes. The life of George Stephenson proves that notwithstanding the novelty and great importance of his improvements in steam transit, he did not " discover" these improvements. He did not discover that a floating embankment would carry a railway across Chat Moss, neither did he discover that the friction between the wheels of a locomotive and the rails would enable a train to be drawn by tractive power alone. Everything connected with his novel history shows that all of his improvements were founded upon a method of reasoning from principles and generally in- ductively. To say that he " discovered " our railway system, according to the ordinary construction of the term, would be to detract from his hard and well-earned reputation, and place him among a class of fortunate schemers, who can claim no place in the history of legitimate engineering. Count Eumford did not by chance develope the philosophy of forces upon which we may say the whole science of dynamics now rests ; he set out upon a methodical plan to demonstrate conceptions that were already matured in his mind, and to verify principles which he had assumed by inductive reasoning. The greater part of really good and substantial improvements, such as have performed any considerable part in developing modern mechanical engineering, have come through this course of first dealing with primary principles, instead of groping about blindly after mechanical expedients, and present circumstances point to a time not far distant when chance discovery will quite disappear. (1.) What change has taken place in the meaning of the name " invention " as applied to machine improvement ? (2.) What should precede an attempt to invent or improve machinery? (3.) In what sense should the name invention be applied to the works of such men as Bentham, Bodmer, or Stephenson ? WORKSHOP EXPERIENCE. 165 CHAPTER XLL WORKSHOP EXPERIENCE. To urge the necessity of learning practical fitting as a part of an engineering education is superfluous. A mechanical engineer who has not been " through the shop " can never expect to attain success, nor command the respect even of the most inferior work- men ; without a power of influencing and controlling others, he is neither fitted to direct construction, nor to manage details of any kind connected with engineering industry. There is nothing that more provokes a feeling of resentment in the mind of a skilled man than to meet with those who have attempted to qualify themselves in the theoretical and commercial details of engineering work, and then assume to direct labour which they do not understand ; nor is a skilled man long in detecting an engineer of this class ; a dozen words in conversation upon any mechanical subject is generally enough to furnish a clue to the amount of practical knowledge possessed by the speaker. As remarked in a previous place, no one can expect to prepare successful designs for machinery, who does not understand the details of its construction ; he should know how each piece is moulded, forged, turned, planed, or bored, and the relative cost of these processes by the different methods which may be adopted. An engineer may direct and control work without a know- ledge of practical fitting, but such control is merely a commercial one, and cannot of course extend to mechanical details which are generally the vital part; the obedience that may thus be enforced in controlling others is not to be confounded with the respect which a superior knowledge of work commands. A gain from learning practical fitting is the confidence which such knowledge inspires in either the direction of work or the preparation of plans for machinery. An engineer who hesitates in his plans for fear of criticism, or who does not feel a perfect confidence in them, will never achieve much success. Improvements, which have totally changed machine fitting during thirty years past, have been of a character to dispense in a great measure with hand skill, and supplant it with what may be termed mental skill. The mere physical effect produced by a man's hands has steadily diminished in value, until it has now 166 WORKSHOP MANIPULATION. almost come to be reckoned in foot-pounds ; but the necessity for practical knowledge instead of being diminished is increased. Formerly an apprentice entered a shop to learn hand skill, and to acquaint himself with a number of mysterious processes ; to learn a series of arbitrary rules which might serve to place him at a disadvantage even with those whose capacity was inferior and who had less education ; but now the whole is changed. An engineer apprentice enters the shop with a confidence that he may learn whatever the facilities afford if he will put forth the required efforts ; there are no mysteries to be solved ; nearly all problems are reached and explained by science, leaving a greater share of the shop-time of a learner to be devoted to studying what is special. This change in engineering pursuits has also produced a change in the workmen almost as thorough as in manipulation. A man who deals with special knowledge only and feels that the secrets of his calling are not governed by systematic rules, by which others may qualify themselves without his assistance, is always more or less narrow-minded and ignorant. The nature of his re- lations to others makes him so ; of this no better proof is wanted than to contrast the intelligence of workmen who are engaged in what may be termed exclusive callings with people whose pursuits are regulated by general rules and principles. A machi- nist of modern times, having outgrown this exclusive idea, has been raised thereby to a social position confessedly superior to that of most other mechanics, so that shop association once so dreaded by those who would otherwise have become mechanics, is no longer an obstacle. Some hints will 'now be given relating to apprentice experience in a workshop, such matters being selected as are most likely to be of interest and use to a learner. Upon entering a shop the first thing to be done is to gain the confidence and the respect of the manager or foreman who has charge of the work ; to gain such confidence and respect is different from, and has nothing to do with, social relations and must depend wholly upon what transpires in the works. To inspire the confidence of a friend one must be kind, faithful, and honourable ; but to command the confidence of a foreman one must be punctual, diligent, and intelligent. There are no more kindly sentiments than those which may be founded on a regard for industry and earnest effort. A learner may have the WORKSHOP EXPERIENCE. 167 misfortune to break tools, spoil work, and fail in every way to satisfy himself, yet if he is punctual, diligent, and manifests an interest in the work, his misfortunes will not cause unkind resentment. It must always be remembered that what is to be learned should not be estimated according to a learner's ideas of its im- portance. A manager and workmen generally look upon fitting as one of the most honourable and intelligent of pursuits, deserv- ing of the respect and best efforts of an apprentice j and while a learner may not think it a serious thing to make a bad fit, or to meet with an accident, his estimate is not the one to judge from. The least word or act which will lead workmen to think that an apprentice is indifferent, at once destroys interest in his success, and cuts off one of the main sources from which information may be derived. An apprentice in entering the workshop should avoid every- thing tending to an appearance of fastidiousness, either of manner or dress ; nothing is more repulsive to workmen, and it may be added, nothing is more out of place in a machine shop than to divide one's time between the work and an attempt to keep clean. An effort to keep as neat as the nature of the work will admit is at all times right, but to dress in clothing not appropriate, or to allow a fear of grease to interfere with the performance of work, is sure to provoke derision. The art of keeping reasonably clean even in a machine shop is worth studying \ some men are greased from head to foot in a few hours, no matter what their work may be ; while others will perform almost any kind of work, and keep clean without sacrific- ing convenience in the least. This difference is the result of habits readily acquired and easily retained. Punctuality costs nothing, and buys a great deal ; a learner who reaches the shop a quarter of an hour before starting time, and spends that time in looking about, manifests thereby an interest in the work, and avails himself of an important privilege, one of the most effectual in gaining shop knowledge. Ten minutes spent in walking about, noting the changes wrought in the work from day to day, furnishes constant material for thought, and ac- quaints a learner with many things which would otherwise escape attention. It requires, however, no little care and discrimination to avoid a kind of resentment which workmen feel in having their work examined, especially if they have met with an accident 168 WORKSHOP MANIPULATION. or made a mistake, and when such inspection is thought to be prompted by curiosity only. The better plan in such cases is to ask permission to examine work in such a way that no one will hear the request except the person addressed such an applica- tion generally will secure both consent and explanation. Politeness is as indispensable to a learner in a machine shop as it is to a gentleman in society. The character of the courtesy may be modified to suit the circumstances and the person, but still it is courtesy. An apprentice may understand differential calculus, but a workman may understand how to bore a steam cylinder ; and in the workman's estimation a problem in cal- culus is a trivial thing to understand compared with the boring of a steam engine cylinder. Under these circumstances, if a work- man is not allowed to balance some of his knowledge against politeness, an apprentice is placed at a disadvantage. Questions and answers constitute the principal medium for ac- quiring technical information, and engineering apprentices should carefully study the philosophy of questions arid answers, just as he does the principles of machinery. Without the art of ques- tioning but slow progress will be made in learning shop manipu- lation. A proper question is one which the person asked will understand, and the answer be understood when it is given ; not an easy rule, but a correct one. The main point is to consider questions before they are asked ; make them relevant to the work in hand, and not too many. To ask frequent questions, is to convey an impression that the answers are not considered, an in- ference which is certainly a fair one, if the questions relate to a subject demanding some consideration. If a man is asked one minute what diametrical pitch means, and the next minute how much cast iron shrinks in cooling, he is very apt to be disgusted, and think the second question not worth answering. It is important, in asking questions, to consider the mood and present occupation of the person addressed ; one question asked when a man's mind is not too much occupied, and when he is in a communicative humour, is worth a dozen questions asked when he is engaged, and not disposed to talk. It is a matter of courtesy in the usages of a shop, and one of expediency to a learner, to ask questions from those who are presumed to be best informed on the subject to which the questions relate ; and it is equally a matter of courtesy to ask questions of different workmen, being careful, however, never to WORKSHOP EXPERIENCE. 169 ask two different persons the same question, nor questions that may call out conflicting answers. There is not a more generous or kindly feeling in the world than that with which a skilled mechanic will share his knowledge with those who have gained his esteem, and who he thinks merit and desire the aid that he can give. An excellent plan to retain what is learned, is to make notes. There is nothing will assist the memory more in learning mechanics than to write down facts as they are learned, even if such memoranda are never referred to after they are made. It is not intended to recommend writing down rules or tables relating to shop manipulation so much as facts which require remark or comment to impress them on the memory writing notes not only assists in committing the subjects to memory, but cultivates a power of composing technical descriptions, a very necessary part of an engineering education. Specifications for engineering work are a most difficult kind of composition and may be made long, tedious, and irrelevant, or concise and lucid. There are also a large number of conventional phrases and endless technicalities to be learned, and to write them will assist in committing them to memory and decide their orthography. In making notes, as much as possible of what is written should be condensed into brief formulae, a form of expression which is fast becoming the written language of machine shops. Reading formulae is in a great degree a matter of habit, like studying mechanical drawings ; that which at the beginning is a maze of complexity, after a time becomes intelligible and clear at a glance. Upon entering the shop, a learner will generally, to use a shop phrase, " be introduced to a hammer and chisel ; " he will, per- haps, regard these hand tools with a kind of contempt. Seeing other operations carried on by power, and the machines in charge of skilled men, he is likely to esteem chipping and filing as of but little importance and mainly intended for keeping apprentices employed. But long after, when a score of years has been added to his experience, the hammer, chisel, and file, will remain the most crucial test of his hand skill, and after learning to mani- pulate power tools of all kinds in the most thorough manner, a few blows with a chipping hammer, or a half-dozen strokes with a file, will not only be a more difficult test of skill, but one most likely to be met with. 170 WORKSHOP MANIPULATION. To learn to chip and file is indispensable, if for no other purpose, to be able to judge of the proficiency of others or to instruct them. Chipping and filing are purely matters of han skill, tedious to learn, but when once acquired, are never forgotten. The use of a file is an interesting problem to study, and one of no little intricacy; in filing across a surface one inch wide, with a file twelve inches long, the pressure required at each end to guide it level may change at each stroke from nothing to twenty pounds or more ; the nice sense of feeling which determines this is a matter of habit acquired by long practice. It is a wonder indeed that true surfaces can be made with a file, or even that a file can be used at all, except for rough work. If asked for advice as to the most important object for an apprentice to aim at in beginning his fitting course, nine out of ten experienced men will say, "to do work well." As power is measured by force and velocity, work is measured by the two conditions of skill and time. The first consideration being, how well a thing may be done, and secondly, in how short a time may it be performed ; the skill spent on a piece of work is the measure of its worth ; if work is badly executed, it makes no difference how short the time of performance has been; this can add nothing to the value of what is done although the expense is diminished. A learner is apt to reverse this proposition at the beginning, and place time before skill, but if he will note what passes around him, it will be seen that criticism is always first directed to the character of work performed. A manager does not ask a workman how long a time was consumed in preparing a piece of work until its character has been passed upon ; in short, the quality of work is its mechanical standard, and the time consumed in preparing work is its commercial standard. A job is never properly done when the workman who performed it can see faults, and in machine fitting, as a rule, the best skill that can be applied is no more than the conditions call for ; so that the first thing to be learned is to perform work well, and afterwards to perform it rapidly. Good fitting is often not so much a question of skill as of the standard which a workman has fixed in his mind, and to which all that he does will more or less conform. If this standard is one of exactness and precision, all that is performed, whether it be filing, turning, planing, or drawing, will come to this standard. This faculty of mind can be defined no further than to say that WORKSHOP EXPERIENCE. 171 it is an aversion to whatever is imperfect, and a love for what is exact and precise. There is no faculty which has so much to do with success in mechanical pursuits, nor is there any trait more susceptible of cultivation. Methodical exactness, reasoning, and persistence are the powers which lead to proficiency in engineer- ing pursuits. There is, perhaps, no more fitting conclusion to these sugges- tions for apprentices than a word about health and strength. It was remarked in connection with the subject of drawing, that the powers of a mechanical engineer were to be measured by his education and mental abilities, no more than by his vitality and physical strength, a proposition which it will be well for an apprentice to keep in mind. One not accustomed to manual labour will, after commencing, find his limbs aching, his hands sore ; he will feel exhausted both at the beginning and at the end of a day's work. These are not dangerous symptoms. He has only to wait until his system is built up so as to sustain this new draught upon its resources, and until nature furnishes a power of endurance, which will in the end be a source of pride, and add a score of years to life. Have plenty of sleep, plenty of plain, substantial food, keep the skin clean and active, laugh at privations, and cultivate a spirit of self-sacrifice and a pride in endurance that will court the hardest and longest efforts. An apprentice who has not the spirit and firmness to endure physical labour, and adapt himself to the conditions of a workshop, should select some pursuit of a nature less aggressive than mechanical engineering. PRINTED BY BALLANTVNE, HANSON AND CO. EDINBURGH AND LONDON BOOKS RELATING TO MACHINE TOOLS AND MANUFACTURING PROCESSES, BY d. 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The Principles of Graphic Statics. By GEORGE SYDENHAM CLARKE, Capt. Royal Engineers. With 112 illustrations. 4to, cloth, 12s. 6d. PUBLISHED BY E. & F. N. SPON. Dynamo- Electric Machinery : A Manual for Students of Electro-technics. By SILVANUS P. THOMPSON, B.A., D.Sc., Professor of Experimental Physics in University College, Bristol, etc., etc. Second edition, illustrated, 8vo, cloth, I2s. 6d. Practical Geometry, Perspective, and Engineering Drawing; a Course of Descriptive Geometry adapted to the Require- ments of the Engineering Draughtsman, including the determination of cast shadows and Isometric Projection, each chapter being followed by numerous examples ; to which are added rules for Shading, Shade-lining, etc., together with practical instructions as to the Lining, Colouring, Printing, and general treatment of Engineering Drawings, with a chapter on drawing Instruments. By GEORGE S. CLARKE, Capt. R.E. Second edition, with 21 plates. 2 vols., cloth, roj. 6d. The Elements of Graphic Statics. By Professor KARL VON OTT, translated from the German by G. S. CLARKE, Capt. R.E., Instructor in Mechanical Drawing, Royal Indian Engineering College. With 93 illustrations, crown 8vo, cloth, 5j. A Practical Treatise on the Mamtfacture and Distri- bution of Coal Gas. By WILLIAM RICHARDS. Demy 410, with numerous wood engravings and 29 plates, cloth, 28^. SYNOPSIS OF CONTENTS : Introduction History of Gas Lighting Chemistry of Gas Manufacture, by Lewis Thompson, Esq., M.R.C.S. Coal, with Analyses, by J. Paterson, Lewis Thompson, and G. R. Hislop, Esqrs. Retorts, Iron and Clay Retort Setting Hydraulic Main Con- densers Exhausters Washers and Scrubbers Purifiers Purification History of Gas Holder Tanks, Brick and Stone, Composite, Concrete, Cast-iron, Compound Annular Wrought-iron Specifications Gas Holders Station M eter Governor Distribution Mains Gas Mathematics, or Formulas for the Distribution of Gas, by Lewis Thompson, Esq. . Services Consumers' Meters Regulators Burners Fittings Photometer Carburization of Gas Air Gas and Water Gas Composition of Coal Gas, by Lewis Thompson, Esq. Analyses of Gas Influence of Atmospheric Pressure and Temperature on Gas Residual Products Appendix Description of Retort Settings, Buildings, etc., etc. The New Formula for Mean Velocity of Discharge of Rivers and Canals. By W. R. K UTTER. Translated from articles in the ' Cultur-Ingenieur,' by Lowis D'A. JACKSON, Assoc. Inst. C.E. 8vo, cloth, I2s. 6d. The Practical Millwright and Engineers Ready Reckoner j or Tables for finding the diameter and power of cog-wheels, diameter, weight, and power of shafts, diameter and strength of bolts, etc. By THOMAS DIXON. Fourth edition, I2mo, cloth, -$s. Tin : Describing the Chief Methods of Mining, Dressing and Smelting it abroad ; with Notes upon Arsenic, Bismuth and Wolfram. By ARTHUR G. CHARLETON, Mem. American Inst, of Mining Engineers. With plates, 8vo, cloth, I2s. 6d. B 3 io CATALOGUE OF SCIENTIFIC BOOKS Perspective, Explained and Illustrated. By G. S. CLARKE, Capt. R.E. With ilhistrations, 8vo, cloth, 3^. 6ct. Practical Hydraulics ; a Series of Rules and Tables for the use of Engineers, etc., etc. By THOMAS Box. Fifth edition, numerous plates, post 8vo, cloth, 5^. The Essential Elements of Practical Mechanics; based OK the Principle of Work, designed for Engineering Students. By OLIVER BYRNE, formerly Professor of Mathematics, College for Civil Engineers. Third edition, with 148 wood engravings, post 8vo, cloth, is. 6d. CONTENTS : Chap. I. How Work is Measured by a Unit, both with and without reference to a Unit of Time Chap. 2. The Work of Living Agents, the Influence of Friction, and introduces one of the most beautiful Laws of Motion Chap. 3- The principles expounded in the first and second chapters are applied to the Motion of Bodies Chap. 4. The Transmission of Work by simple Machines Chap. 5. Useful Propositions and Rules. Breweries and Mailings : their Arrangement, Con- struction, Machinery, and Plant. By G. SCAMELL, F.R.I.B.A. Second edition, revised, enlarged, and partly rewritten. By F. COLYER, M.I.C.E., M.I.M.E. With 20 plates, 8vo, cloth, iSs. A Practical Treatise on the Construction of Hori- zontal and Vertical Waterwheels, specially designed for the use of opera- tive mechanics. By WILLIAM CULLEN, Millwright and Engineer. With II plates. Second edition, revised and enlarged, small 4to, cloth, 12s. 6d. A Practical Treatise on Mill-gearing, Wheels, Shafts, Riggers, etc.', for the use of Engineers. By THOMAS Box. Third edition, with 1 1 plates. Crown 8vo, cloth, is. 6d. Mining Machinery: a Descriptive Treatise on the Machinery, Tools, and other Appliances used in Mining. By G. G. ANDRE, F.G.S., Assoc. Inst. C.E., Mem. of the Society of Engineers. Royal 4to, uniform with the Author's Treatise on Coal Mining, con- taining 182 plates, accurately drawn to scale, with descriptive text, in 2 vols., cloth, 3/. I2J. CONTENTS : Machinery for Prospecting, Excavating, Hauling, and Hoisting Ventilation Pumping Treatment of Mineral Products, including Gold and Silver, Copper, Tin, and Lead, Iron Coal, Sulphur, China Clay, Brick Earth, etc. Tables for Setting out Curves for Railways, Canals, Roads, etc., varying from a radius of five chains to three miles. By A. KENNEDY and R. W. HACKWOOD. Illustrated, 32mo, cloth, 2s. 6d. PUBLISHED BY E. & F. N. SPON. n The Science and Art of the Manufacture of Portland Cement, with observations on some of its constructive applications. With 66 illustrations. By HENRY REID, C.E., Author of 'A Practical Treatise on Concrete,' etc., etc. 8vo, cloth, i8j. The Draughtsman!* Handbook of Plan and Map Drawing ; including instructions for the preparation of Engineering, Architectural, and Mechanical Drawings. With numerous illustration* in the text, and 33 plates (15 printed in colours}. By G. G. ANDRE. F.G.S., Assoc. Inst. C.E. 410, cloth, gs. CONTENTS: The Drawing Office and its Furnishings Geometrical Problems Lines, Dots, and their Combinations Colours, Shading, Lettering, Bordering, and North Points Scales Plotting Civil Engineers' and Surveyors' Plans Map Drawing Mechanical and Architectural Drawing Copying and Reducing Trigonometrical Formulae, etc., etc. The B oiler-maker s andiron Ship-builder s Companion, comprising a series of original and carefully calculated tables, of the utmost utility to persons interested in the iron trades. By JAMES FODEN, author of ' Mechanical Tables,' etc. Second edition revised, with illustra- tions, crown 8vo, cloth, $s. Rock Blasting: a Practical Treatise on the means employed in Blasting Rocks for Industrial Purposes. By G. G. ANDRE, F.G.S., Assoc. Inst. C.E. With 56 illustrations and 12 plates, 8vo, cloth, 10*. bd. Painting and Painters Manual: a Book of Facts for Painters and those who Use or Deal in Paint Materials. By C. L. CONDIT and J. SCHELLER. Illustrated, 8vo, cloth, IQJ. 6d. A Treatise on Ropemaking as practised in public and private Rope-yards, with a Description of the Manufacture, Rules, Tables of Weights, etc., adapted to the Trade, Shipping, Mining, Railways, Builders, etc. By R. CHAPMAN, formerly foreman to Messrs. Huddart and Co., Limehouse, and late Master Ropemaker to H.M. Dockyard, Deptford. Second edition, I2mo, cloth, 3J-. Laoctons Builders and Contractors Tables ; for the use of Engineers, Architects, Surveyors, Builders, Land Agents, and others. Bricklayer, containing 22 tables, with nearly 30,000 calculations. 4to, cloth, 5-r. Laxtori s Bidlders and Contractors Tables. Ex- cavator, Earth, Land, Water, and Gas, containing 53 tables, with nearly 24,000 calculations. 4to, cloth, 5-r. B 4 12 CATALOGUE OF SCIENTIFIC BOOKS Sanitary Engineering: a Guide to the Construction of Works of Sewerage and House Drainage, with Tables for facilitating the calculations of the Engineer. By BALDWIN LATHAM, C.E., M. Inst. C.E., F.G.S., F.M.S., Past-President of the Society of Engineers. Second edition, with numerous plates and woodcuts, 8vo, cloth, I/. IQJ-. Screw Cutting Tables for Engineers and Machinists, giving the values of the different trains of Wheels required to produce Screws of any pitch, calculated by Lord Lindsay, M.P., F.R.S., F.R.A.S., etc. Cloth, oblong, 2s. Screw Cutting Tables, for the use of Mechanical Engineers, showing the proper arrangement of Wheels for cutting the Threads of Screws of any required pitch, with a Table for making the Universal Gas-pipe Threads and Taps. By W. A. MARTIN, Engineer. Second edition, oblong, cloth, is., or sewed, 6d. A Treatise on a Practical Method of Designing Slide- Valve Gears by Simple Geometrical Constrtiction, based upon the principles enunciated in Euclid's Elements, and comprising the various forms of Plain Slide-Valve and Expansion Gearing ; together with Stephenson's, Gooch's, and Allan's Link-Motions, as applied either to reversing or to variable expansion combinations. By EDWARD J. COWLING WELCH, Memb. Inst. Mechanical Engineers. Crown 8vo, cloth, 6s. Cleaning and Scouring : a Manual for Dyers, Laun- dresses, and for Domestic Use. By S. CHRISTOPHER. i8mo, sewed, 6d. A Glossary of Terms used in Coal Mining. By WILLIAM STUKELEY GRESLEY, Assoc. Mem. Inst. C.E., F.G.S., Member of the North of England Institute of Mining Engineers. Illustrated with numerous woodcuts and diagrams, crown 8vo, cloth, $s. A Pocket-Book for Boiler Makers and Steam Users, comprising a variety of useful information for Employer and Workman, Government Inspectors, Board of Trade Surveyors, Engineers in charge of Works and Slips, Foremen of Manufactories, and the general Steam- using Public. By MAURICE JOHN SEXTON. Second edition, royal 32mo, roan, gilt edges, 5-r. Electrolysis: a Practical Treatise on Nickeling, Coppering, Gilding, Silvering, the Refining of Metals, and the treatment of Ores by means of Electricity. By HIPPOLYTE FONTAINE, translated from the French by J. A. BERLY, C.E., Assoc. S.T.E. With engravings. 8vo, cloth, 9*. PUBLISHED BY E. & F. N. SPON. 13 Barlow s Tables of Squares, Cubes, Square Roots, Cube Roots, Reciprocals of all Integer Numbers up to 10,000. Post 8vo, cloth, 6s. A Practical Treatise on the Steam Engine, con- taining Plans and Arrangements of Details for Fixed Steam Engines, with Essays on the Principles involved in Design and Construction. By ARTHUR 'RIGG, Engineer, Member of the Society of Engineers and of the Royal Institution of Great Britain. Demy 4to, copiously illustrated with woodcuts and 96 plates, in one Volume, half-bound morocco, 2/. 2s. ; or cheaper edition, cloth, 2$s. This work is not, in any sense, an elementary treatise, or history of the steam engine, but is intended to describe examples of Fixed Steam Engines without entering into the wide domain of locomotive or marine practice. To this end illustrations will be given of the most recent arrangements of Horizontal, Vertical, Beam, Pumping, Winding, Portable, Semi- portable, Corliss, Allen, Compound, and other similar Engines, by the most eminent Firms in Great Britain and America. The laws relating to the action and precautions to be observed in the construction of the various details, such as Cylinders, Pistons, Piston-rods, Connecting- rods, Cross-heads, Motion-blocks, Eccentrics, Simple, Expansion, Balanced, and Equilibrium Slide-valves, and Valve-gearing will be minutely dealt with. In this connection will be found articles upon the Velocity of Reciprocating Parts and the Mode of Applying the Indicator, Heat and Expansion of Steam Governors, and the like. It is the writer's desire to draw illustrations from every possible source, and give only those rules that present practice deems correct. A Practical Treatise on the Science of Land and Engineering Surveying, Levelling, Estimating Quantities, etc., with a general description of the several Instruments required for Surveying, Levelling, Plotting, etc. By H. S. MERRETT. Fourth edition, revised by G. W. USILL, Assoc. Mem. Inst. C.E. 41 plates, with illustrations and tables, royal 8vo, cloth, I2s. 6d. PRINCIPAL CONTENTS : Part i. Introduction and the Principles of Geometry. Part 2. Land Surveying; com- prising General Observations The Chain Offsets Surveying by the Chain only Surveying Hilly Ground To Survey an Estate or Parish by the Chain only Surveying with the Theodolite Mining and Town Surveying Railroad Surveying Mapping Division and Laying out of Land Observations on Enclosures Plane Trigonometry. Part 3. Levelling Simple and Compound Levelling The Level Book Parliamentary Plan and Section Levelling with a Theodolite Gradients Wooden Curves To Lay out a Railway Curve- Setting out Widths. Part 4. Calculating Quantities generally for Estimates Cuttings and Embankments Tunnels Brickwork Ironwork Timber Measuring. Part 5. Description and Use of Instruments in Surveying and Plotting The Improved Dumpy Level Troughton's Level The Prismatic Compass Proportional Compass Box Sextant Vernier Panta- graph Merrett's Improved Quadrant Improved Computation Scale The Diagonal Scale Straight Edge and Sector. Part 6. Logarithms of Numbers Logarithmic Sines and Co-Sines, Tangents and Co-TangentsNatural Sines and Co-SinesTables for Earthwork, for Setting out Curves, and for various Calculations, etc., etc., etc. Health and Comfort in House Building, or Ventila- tion with Warm Air by Self-Acting Suction Power, with Review of the mode of Calculating the Draught in Hot- Air Flues, and with some actual Experiments. By J. DRYSDALE, M.D., and J. W. HAYWARD, M.D. Second edition, with Supplement, with plates, demy 8vo, cloth, Js. 6d. 14 CATALOGUE OF SCIENTIFIC BOOKS. The Assayers Manual: an Abridged Treatise on the Docimastic Examination of Ores and Furnace and other Artificial Products. By BRUNO KERL. Translated by W. T. BRANNT. With 65 illustrations, 8vo, cloth, I2s. 6d. Electricity: its Theory, Sources, and Applications. By J. T. SPRAGUE, M.S.T.E. Second edition, revised and enlarged, with numerous illustrations, crown 8vo, cloth, 15^. The Practice of Hand Turning in Wood, Ivory, Shell, etc., with Instructions for Turning such Work in Metal as may be required in the Practice of Turning in Wood, Ivory, etc. ; also an Appendix on Ornamental Turning. (A book for beginners.) By FRANCIS CAMPIN. Third edition, with wood engravings, crown 8vo, cloth, 6s. CONTENTS : On Lathes Turning Tools Turning Wood Drilling Screw Cutting Miscellaneous Apparatus and Processes Turning Particular Forms Staining Polishing Spinning Metals Materials Ornamental Turning, etc. Treatise on Watchwork, Past and Present. By the Rev. H. L. NELTHROPP, M.A., F.S.A. With 32 illustrations, crown 8vo, cloth, 6s. 6d. CONTENTS : Definitions of Words and Terms used in Watchwork Tools Time Historical Sum- mary-!-On Calculations of the Numbers for Wheels and Pinions ; their Proportional Sizes, Trains, etc. Of Dial Wheels, or Motion Work Length of Time of Going without Winding up The Verge The Horizontal The Duplex The Lever The Chronometer Repeating ^yatches Keyless Watches The Pendulum, or Spiral Spring Compensation Jewelling of Pivot Holes Clerkenwell Fallacies of the Trade Incapacity of Workmen How to Choose and Use a Watch, etc. Algebra Self -Taught. By W. P. HIGGS, M.A., D.Sc., LL.D., Assoc. Inst. C.E., Author of ' A Handbook of the Differ- ential Calculus,' etc. Second edition, crown 8vo, cloth, 2s. 6d. CONTENTS : Symbols and the Signs of Operation The Equation and the Unknown Quantity Positive and Negative Quantities Multiplication Involution Exponents Negative Expo- nents Roots, and the Use of Exponents as Logarithms Logarithms Tables of Logarithms and Proportionate Parts Transformation of System of Logarithms Common Uses of Common Logarithms Compound Multiplication and the Binomial Theorem Division, Fractions, and Ratio Continued Proportion The Series and the Summation of the Series Limit of Series Square and Cube Roots Equations List of Formulae, etc. Spans' Dictionary of Engineering, Civil, Mechanical, Military, and Naval; with technical terms in French, German, Italian, and Spanish, 3100 pp., and nearly 8000 engravings, in super-royal 8vo, in 8 divisions, $/. 8j. Complete in 3 vols., cloth, $/. 5^. Bound in a superior manner, half-morocco, top edge gilt, 3 vols., 61. I2s. PUBLISHED BY E. & F. N. SPON. 15 Notes in Mechanical Engineering. Compiled prin- cipally for the use of the Students attending the Classes on this subject at the City of London College. By HENRY ADAMS, Mem. Inst. M.E., Mem. Inst. C.E., Mem. Soc. of Engineers. Crown 8vo, cloth, 2s. 6d. Canoe and Boat Building: a complete Manual for Amateurs, containing plain and comprehensive directions for the con- struction of Canoes, Rowing and Sailing Boats, and Hunting Craft. By W. P. STEPHENS. With numerous illustrations and 24 plates of Working Drawings. Crown 8vo, cloth, "js. 6d. Proceedings of the National Conference of Electricians, Philadelphia, October 8th to I3th, 1884. i8mo, cloth, 3^. Dynamo - Electricity, its Generation, Application, Transmission, Storage, and Measurement. By G. B. PRESCOTT. With 545 illustrations. 8vo, cloth, I/, is. Domestic Electricity for Amateurs. Translated from the French of E. HOSPITALIER, Editor of "L'Electricien," by C. J. WHARTON, Assoc. Soc. Tel. Eng. Numerous illustrations. Demy 8vo, cloth, 9-r. CONTENTS : i. Production of the Electric Current 2. Electric Bells 3. Automatic Alarms 4. Domestic Telephones 5. Electric Clocks 6. Electric Lighters 7. Domestic Electric Lighting 8. Domestic Application of the Electric Light 9. Electric Motors -10. Electrical Locomo- tion ii. Electrotyping, Plating, and Gilding 12. Electric Recreations 13. Various appli- cations Workshop of the Electrician. Wrinkles in Electric Lighting. By VINCENT STEPHEN. With illustrations. i8mo, cloth, 2s. 6d. CONTENTS : i. The Electric Current and its production by Chemical means 2. Production of Electric Currents by Mechanical means 3. Dynamo-Electric Machines 4. Electric Lamps 5. Lead 6. Ship Lighting. The Practical Flax Spinner ; being a Description of the Growth, Manipulation, and Spinning of Flax and Tow. By LESLIE C. MARSHALL, of Belfast. With illustrations. 8vo, cloth, 15-$-. Foundations and Foundation Walls for all classes of Buildings, Pile Driving, Building Stones and Bricks, Pier and Wall construction, Mortars, Limes, Cements, Concretes, Stuccos, &c. 64 illus- trations. By G. T. POWELL and F. BAUMAN. 8vo, cloth, los. 6d. 1 6 CATALOGUE OF SCIENTIFIC BOOKS Manual for Gas Engineering Students. By D. LEE. i8mo, cloth is. Hydraulic Machinery, Past and Present. A Lecture delivered to the London and Suburban Railway Officials' Association. By H. ADAMS, Mem. Inst. C.E. Folding plate. 8vo, sewed, is. Twenty Years with the Indicator. By THOMAS PRAY, Jun., C.E., M.E., Member of the American Society of Civil Engineers. 2 vols., royal 8vo, cloth, i2s. 6d. Annual Statistical Report of the Secretary to the Members of the Iron and Steel Association on the Home and Foreign Iron and Steel Industries in 1884. Issued March 1885. 8vo, sewed, 5.?. Bad Drains, and How to Test them ; with Notes on the Ventilation of Sewers, Drains, and Sanitary Fittings, and the Origin and Transmission of Zymotic Disease. By R. HARRIS REEVES. Crown 8vo, cloth, 3-y. 6d. Standard Practical Plumbing ; being a complete Encyclopaedia for Practical Plumbers and Guide for Architects, Builders, Gas Fitters, Hot-water Fitters, Ironmongers, Lead Burners, Sanitary Engineers, Zinc Workers, &c. Illustrated by over 2000 engravings. By P. J. DAVIES. Vol. I, royal 8vo, cloth, "js. 6d. Pneumatic Transmission of Messages and Parcels between Paris and London, via Calais and Dover. By J. B. BERLIER, C.E. Small folio, sewed, 6d. List of Tests (Reagents), arranged in alphabetical order, according to the names of the originators. Designed especially for the convenient reference of Chemists, Pharmacists, and Scientists. By HANS M. WILDER. Crown 8vo, cloth, 45-. 6d. Ten Years Experience in Works of Intermittent Downward Filtration. By J. BAILEY DENTON, Mem. Inst. C.E. Second edition, with additions. Royal 8vo, sewed, 4^. A Treatise on the Manufacture of Soap and Candles, Ltibricants and Glycerin. By W. LANT CARPENTER, B.A., B.Sc. (late of Messrs. C. Thomas and Brothers, Bristol). With illustrations. Crown 8vo, cloth, lew. 6^. PUBLISHED BY E. & F. N. SPON. 17 The Stability of Ships explained simply, and calculated by a neiv Graphic method. By J. C. SPENCE, M.I.N.A. 410, sewed, ' Steam Making, or Boiler Practice. By CHARLES A. SMITH, C.E. 8vo, cloth, IQJ. 6d. CONTENTS : i. The Nature of Heat and the Properties of Steam 2. Combustion. 3. Externally Fired Stationary Boilers 4. Internally Fired Stationary Boilers 5. Internally Fired Portable Locomotive and Marine Boilers 6. Design, Construction, and Strength of Boilers 7. Pro- portions of Heating Surface, Economic Evaporation, Explosions 8. Miscellaneous Boilers, Choice of Boiler Fittings and Appurtenances. The Firemans Guide ; a Handbook on the Care of Boilers. By TEKNOLOG, foreningen T. I. Stockholm. Translated from the third edition, and revised by KARL P. DAHLSTROM, M.E. Second edition. Fcap. 8vo, cloth, 2s. A Treatise on Modern Steam Engines and Boilers, including Land Locomotive, and Marine Engines and Boilers, for the use of Students. By FREDERICK COLYER, M. Inst. C.E., Mem. Inst. M.E. With 36 plaits. 4to, cloth, 2$s. CONTENTS: Introduction 2. ion 2. Original Engines 3. Boilers 4. High-Pressure Beam Engines 5. Cornish Beam Engines 6. Horizontal Engines 7. Oscillating Engines 8. Vertical High- Pressure Engines 9. Special Engines 10. Portable Engines u. Locomotive Engines 12. Marine Engines. Steam Engine Management; a Treatise on the Working and Management of Steam Boilers. By F. COLYER, M. Inst. C.E., Mem. Inst. M.E. i8mo, cloth, 2s. Land Surveying on the Meridian and Perpendicular System. By "WILLIAM PENMAN, C.E. 8vo, cloth, 8s. 6d. The Topographer, his Instruments and Methods, designed for the use of Students, Amateur Photographers, Surveyors, Engineers, and all persons interested in the location and construction of works based upon Topography. Ilhtstrated with mimerotts plates, maps, and engravings. By LEWIS M. HAUPT, A.M. 8vo, cloth, iSs. A Text-Book of Tanning, embracing the Preparation of all kinds of Leather. By HARRY R. PROCTOR, F.C.S., of Low Lights Tanneries. With illustrations. Crown 8vo, cloth, los. 6d. In super-royal 8vo, 1168 pp., -with 2400 illustrations, in 3 Divisions, cloth, price 13*. 6d. each ; or i vol., cloth, a/. ; or half-morocco, -2!. 8s. A SUPPLEMENT TO SPONS' DICTIONARY OF ENGINEERING. EDITED BY ERNEST SPON, MEMB. Soc. ENGINEERS. Abacus, Counters, Speed Indicators, and Slide Rule. Agricultural Implements and Machinery. Air Compressors. Animal Charcoal Ma- chinery. Antimony. Axles and Axle-boxes. Barn Machinery. Belts and Belting. Blasting. Boilers. Brakes. Brick Machinery. Bridges. 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Oils and Fatty Sub- Varnish, 15 pp. Fibrous Substances, 92 stances, 125 pp. Vinegar, 5 pp. pp. 79 figs. Paint. Wax, 5 pp. Floor-cloth, 1 6 pp. 21 Paper, 26 pp. 23 figs. Wool, 2 pp. figs. Paraffin, 8 pp. 6 figs. Woollen Manufactures, Food Preservation, 8 pp. Pearl and Coral, 8 pp. 58 pp. 39 figs. Fruit, 8 pp. Perfumes, 10 pp. London : E. & F. N. SPON, 125, Strand. New York : 35, Murray Street. Crown 8vo, cloth, with illustrations, 5.5-. WORKSHOP RECEIPTS, FIRST SERIES. BY ERNEST SPON. SYNOPSIS OF CONTENTS. Bookbinding. Bronzes and Bronzing Candles. Cement. Cleaning. Colourwashing. Concretes. Dipping Acids. Drawing Office Details. Drying Oils. Dynamite. Electro - Metallurgy {Cleaning, Dipping, Scratch-brushing, Bat- teries, Baths, and ( Deposits of every j description). Enamels. Engraving on Wood, Copper, Gold, Silver, ' Steel, and Stone. Etching and Aqua Tint. Firework Making j (Rockets, Stars, Rains, \ Gerbes, Jets, Tour- j billons, Candles, Fires, | Lances,Lights, Wheels, ! Fire-balloons, and' minor Fireworks). Fluxes. Foundry Mixtures. Besides Receipts relating to the lesser Technological matters and processes, such as the manufacture and. use of Stencil Plates, Blacking, Crayons, Paste, Putty, Wax, Size, Alloys, Catgut, Tunbridge Ware, Picture Frame and Architectural Mouldings, Compos, Cameos, and others too numerous to mention. Freezing. Fulminates. Furniture Creams, Oils, Polishes, Lacquers, and Pastes. Gilding. Glass Cutting, Cleaning, Frosting, Drilling, Darkening, Bending, Staining, and Paint- ing. Glass Making. Glues. Gold. Graining. Gums. Gun Cotton. Gunpowder. Horn Working. Indiarubber. Japans, Japanning, and kindred processes. Lacquers. Lathing. Lubricants. Marble Working. Matches. Mortars. Nitre-Glycerine. Oils. Paper. Paper Hanging. Painting in Oils, in Water Colours, as well as Fresco, House, Trans- parency, Sign, and Carriage Painting. Photography. Plastering. Polishes. Pottery (Clays, Bodies, Glazes, Colours, Oils, Stains, Fluxes, Ena- mels, and Lustres). Scouring. Silvering. Soap. Solders. Tanning. Taxidermy. Tempering Metals. Treating Horn, Mother- o'- Pearl, and like sub- stances. Varnishes, Manufacture and Use of. Veneering. Washing. Waterproofing. Welding. London: E. & F. N. SPON, 125, Strand. New York: 35, Murray Street. Crown 8vo, cloth, 485 pages, with illustrations, 5-r. WORKSHOP RECEIPTS, SECOND SERIES. BY ROBERT HALDANE. SYNOPSIS OF CONTENTS.- Acidimetry and Alkali- Disinfectants. Isinglass. metry. Dyeing, Staining, and Ivory substitutes. Albumen. Colouring. Leather. Alcohol. Essences. Luminous bodies. Alkaloids. Extracts. Magnesia. Baking-powders. Fireproofing. Matches. Bitters. Gelatine, Glue, and Size. Paper. Bleaching. Glycerine. Parchment. Boiler Incrustations. Gut. Perchloric acid. Cements and Lutes. Hydrogen peroxide. Potassium oxalate. Cleansing. Ink. Preserving. Confectionery. Iodine. Copying. lodoform. Pigments, Paint, and Painting : embracing the preparation of Pigments^ including alumina lakes, blacks (animal, bone, Frankfort, ivory, lamp, sight, soot), blues (antimony, Antwerp, cobalt, cseruleum, Egyptian r manganate, Paris, Peligot, Prussian, smalt, ultramarine), browns (bistre 7 hinau, sepia, sienna, umber, Vandyke), greens (baryta, Brighton, Brunswick, chrome, cobalt, Douglas, emerald, manganese, mitis, mountain, Prussian, sap, Scheele's, Schweinfurth, titanium,' verdigris, zinc), reds (Brazilwood lake, carminated lake, carmine, Cassius purple, cobalt pink, cochineal lake, colco- thar, Indian red, madder lake, red chalk, red lead, vermilion), whites (alum r baryta, Chinese, lead sulphate, white lead by American, Dutch, French r German, Kremnitz, and Pattinson processes, precautions in making, and composition of commercial samples whiting, Wilkinson's white, zinc white), yellows (chrome, gamboge, Naples, orpiment, realgar, yellow lakes) ; Paint (vehicles, testing oils, driers, grinding, storing, applying, priming, drying, filling, coats, brushes, surface, water-colours, removing smell, discoloration - T miscellaneous paints cement paint for carton-pierre, copper paint, gold paint, iron paint, lime paints, silicated paints, steatite paint, transparent paints, tungsten paints, window paint, zinc paints) ; Painting (general instructions, proportions of ingredients, measuring paint work ; carriage painting priming, paint, best putty, finishing colour, cause of cracking, mixing the paints, oils, driers, and colours, varnishing, importance of washing vehicles, re-varnishing,. how to dry paint ; woodwork painting). London : E. & F. N. SPON, 125, Strand, New York : 35, Murray Street. JUST PUBLISHED. Crown 8vo, cloth, 480 pages, with 183 illustrations, $j. WORKSHOP RECEIPTS, THIRD SERIES. BY C. G. WARNFORD LOCK. Uniform with the First and Second Series. Alloys. Aluminium. Antimony. Barium. Beryllium. Bismuth. Cadmium. Caesium. Calcium. Cerium. Chromium. Cobalt. Copper. Didymium. Electrics. Enamels and Glazes. Erbium. Gallium. Glass. Gold. London : E. & F. N. SPON, 125, Strand. New York: 35, Murray Street. SYNOPSIS OF CONTENTS. Indium. ; Rubidium. Iridium. Ruthenium. Iron and Steel. Selenium. Lacquers and Lacquering. Silver. Lanthanum. Slag. Lead. Sodium. Lithium. Strontium. Lubricants. Tantalum. Magnesium. , Terbium. Manganese. Thallium. Mercury. Thorium. Mica. Tin. Molybdenum. Titanium. Nickel. Tungsten. Niobium. Uranium. Osmium. Vanadium. Palladium. Yttrium. Platinum. Zinc. Potassium. Zirconium. Rhodium. WORKSHOP RECEIPTS, FOURTH SERIES, DEVOTED MAINLY TO HANDICRAFTS & MECHANICAL SUBJECTS. BY C. G. WARNFORD LOCK. 250 Illustrations, with Complete Index, and a General Index to the Four Series, 5s. Waterproofing rubber goods, cuprammonium processes, miscellaneous preparations. Packing and Storing articles of delicate odour or colour, of a deliquescent character, liable to ignition, apt to suffer from insects or damp, or easily broken. Embalming and Preserving anatomical specimens. Leather Polishes. Cooling Air and Water, producing low temperatures, making ice, cooling syrups and solutions, and separating salts from liquors by refrigeration. Pumps and Siphons, embracing every useful contrivance for raising and supplying water on a moderate scale, and moving corrosive, tenacious, and other liquids. Desiccating air- and water-ovens, and other appliances for drying natural and artificial products. Distilling water, tinctures, extracts, pharmaceutical preparations, essences, perfumes, and alcoholic liquids. Emulsifying as required by pharmacists and photographers. Evaporating saline and other solutions, and liquids demanding special precautions. Piltering water, and solutions of various kinds. Percolating and Macerating. Electrotyping. Stereotyping by both plaster and paper processes. Bookbinding in all its details. Straw Plaiting and the fabrication of baskets, matting, etc. Musical Instruments the preservation, tuning, and repair of pianos, harmoniums, musical boxes, etc. Clock and Watch Mending adapted for intelligent amateurs. Photography recent development in rapid processes, handy apparatus, numerous recipes for sensitizing and developing solutions, and applica- tions to modern illustrative purposes. London : E. & F. N. SPON, 125, Strand. New York : 35, Murray Street. JUST In demy 8vo, cloth, 600 pages, and 1420 Illustrations, 6s. SPONS' MECHANICS' OWN BOOK; A MANUAL FOR HANDICRAFTSMEN AND AMATEURS. CONTENTS. Mechanical Drawing Casting and Founding in Iron, Brass, Bronze, and other Alloys Forging and Finishing Iron Sheetmetal Working Soldering, Brazing, and Burning Carpentry and Joinery, embracing descriptions of some 400 Woods, over 200 Illustrations of Tools and their uses, Explanations (with Diagrams) of 116 joints and hinges, and Details of Construction of Workshop appliances, rough furniture, Garden and Yard Erections, and House Building Cabinet-Making and Veneering Carving and Fretcutting Upholstery Painting, Graining, and Marbling Staining Furniture, Woods, Floors, and Fittings Gilding, dead and bright, on various grounds Polishing Marble, Metals, and Wood Varnishing Mechanical movements, illustrating contrivances for transmitting motion Turning in Wood and Metals Masonry, embracing Stonework, Brickwork, Terracotta, and Concrete Roofing with Thatch, Tiles, Slates, Felt, Zinc, &c. Glazing with and without putty, and lead glazing Plastering and Whitewashing Paper-hanging Gas-fitting Bell-hanging, ordinary and electric Systems Lighting Warming Ventilating Roads, Pavements, and Bridges Hedges, Ditches, and Drains Water Supply and Sanitation Hints on House Construction suited to new countries. London : E. & F. N. SPON, 125, Strand. New York : 35, Murray Street. THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW AN INITIAL FINE OF 25 CENTS WILL BE ASSESSED FOR FAILURE TO RETURN THIS BOOK ON THE DATE DUE. THE PENALTY WILL INCREASE TO SO CENTS ON THE FOURTH DAY AND TO $1.OO ON THE SEVENTH DAY OVERDUE. 1945 LD 21-y5m-7,'37 v/jr*> i r^o^ /- YB i ooou UNIVERSITY OF CALIFORNIA LIBRARY