MOTORS AH 
 MOTORING 
 
 HENRY J . SPOONER
 
 CHESTKR H. HEUSER, 
 
 THE WISTAR INSTITUTE 
 
 PHILADELPHIA, PA.
 
 MOTORS AND MOTORING
 
 Volumes now ready: 
 BALLOONS, AIRSHIPS, AND FLYING MACHINES. 
 
 By GERTRUDE BACON. 
 MOTORS AND MOTORING. By Professor HENKY SPOONER, 
 
 C.E., F.G.S. 
 
 RADIUM. By DR. HAMPSON. 
 
 WIRELESS TELEGRAPHY. By S. G. BUBBOW. 
 And Others in Preparation.
 
 MOTORS 
 
 AND 
 
 MOTORING 
 
 BY 
 HENRY J. SPQ/ONER, C.E. 
 
 M.INST.M.E., A.M.INST.C.E.. 
 F.O.S. 
 
 NEW YORK 
 DODD, MEAD & COMPANY 
 
 1908
 
 COPYHIGHT, 1905, 
 BY 
 
 DODD, MEAD & COMPANY
 
 PREFACE 
 
 WITH the object of assisting beginners to acquire use- 
 ful information relating to motors and motoring, the 
 author consented to write this little work, much of the 
 matter consisting of what may be considered an intro- 
 duction to the mechanics of motoring. He has endeav- 
 ored to explain things in non-technical language as far 
 as practicable, and in such a way that those who have 
 not the time, inclination, or opportunity to study any 
 of the large books on the subject, may easily be able 
 to get a general grasp of the principles which underlie 
 the construction, assembling, and working of gasolene 
 cars. 
 
 The Gasolene Engine System is first dealt with, and 
 a careful examination of Fig. 1, with the assistance of 
 the accompanying text, should enable the reader to 
 understand the relationship and interdependence of its 
 various parts; these parts being further dealt with in 
 separate articles, not the least important of which is 
 No. 12, on the Float-Feed Carburettor, which is ex- 
 plained with the assistance of Fig. 6, specially devised 
 to show, on a single drawing, the important features of 
 the best-known carburettors, an expedient the author 
 has found very useful for educational purposes. 
 
 Most of the figures are diagrammatic, and have been 
 drawn in such a way as to give prominence to their im- 
 portant features, whilst, for simplicity sake, minor de- 
 tails have been omitted; the leading parts being shaped 
 that their functions can be best understood by the 
 novice, and these remarks particularly apply to Figs. 
 18 and 19. 
 
 No attempt has been made to describe any particular 
 car, as the details of construction of any one make nec- 
 vii
 
 viii PREFACE 
 
 essarily differ in many respects from all others. But 
 the author hopes that the contents of the following 
 pages will help the novice to trace out easily the run of 
 the various connections, pipes, leads, etc., on a given 
 car, and to understand quickly its general arrangement 
 and working, and also become acquainted with the 
 methods of adjustment and lubrication peculiar to it. 
 All this can be much facilitated by referring to the In- 
 struction Books now supplied with most cars, and by 
 reading week by week one or more of the admirable 
 technical journals which so loyally and ably represent, 
 promote, and encourage the pastime and industry. 
 Although, due to the exigencies of space, the author 
 has had to confine himself mainly to motor cars, it 
 should not be overlooked that gasolene motors, whether 
 they be used to propel cars, boats, cycles, or machinery, 
 have much in common.
 
 ILLUSTRATIONS 
 
 PAGE 
 
 Fig. 1. DlAGEAMATIC SKETCH OF THE COMPLETE GASO- 
 LENE MOTOR SYSTEM, 5 
 
 Figs. 2 to 5. DIAGRAMMATIC DRAWINGS SHOWING THE 
 
 FOUR STROKES OF THE OTTO CYCLE 9 
 
 Fig. 6. FLOAT-FEED CARBURETTOR, 19 
 
 Fig. 7. THE DE DION SURFACE CARBURETTOR, ... 25 
 Figs. 8 to 10. MIXING CHAMBER OR TWIN TAP OF DE DION 
 
 CARBURETTOR, 27 
 
 Fig. 11. SPARKING PLUG 43 
 
 Fig. 12. NORMAL INDICATOR DIAGRAM GOOD IGNITION, . 53 
 
 Fig. 13. INDICATOR DIAGRAM LATE IGNITION, .... 53 
 
 Fig. 14. INDICATOR DIAGRAM PRE-IGNITION, 53 
 
 Fig 15. INDICATOR DIAGRAM BACK-FIRING, 53 
 
 Fig. 16. COMMUTATOR, OH CURRENT DISTRIBUTOR (PAN- 
 
 iiARD TYPE), 55 
 
 Fig. 17. TYPICAL MUFFLER, 62 
 
 Fig. 18. DRIVE-THROUGH SIDE CHAINS, 66 
 
 Fig. 19. LIVE AXLE OR CARDAN DRIVE, 68 
 
 Fig. 20. PANHARD CLUTCH 72
 
 INTRODUCTION 
 
 1. No one can fail to notice the growing interest the 
 typical "man in the street" is taking in Motors 1 and 
 Motoring. His eyes instinctively turn critically to view 
 each passing car, and he knows that a peculiar ticking 
 noise is a sure indication of the approach of an electric 
 carriage, and light puffs of steam from underneath a 
 car 2 a certain sign that it is a steam vehicle, whilst his 
 ear is so delicately attuned to the wide range of detona- 
 tions, due to the working of gasolene motors, that he is 
 rarely at fault in placing such cars in the right cate- 
 gory; but should he be in doubt, the offensive odor 3 of 
 the exhaust gases from the cars too often give his olfac- 
 tory organ an opportunity of assisting in the matter, 
 and he is generally able to differentiate between the 
 various types of cars in use. Presumably he has not 
 failed to notice that the electric car is used almost ex- 
 clusively for town work, often in the form of a 
 brougham. Its great weight for a comparatively small 
 power, the limited distance it can run without recharg- 
 ing the batteries, to say nothing of its cost, and the cost 
 of running, precludes this otherwise almost perfect car 
 from use for touring purposes, so that for long dis- 
 
 1 Motor is a recognized abbreviation of " Motor Car " ; 
 strictly speaking, the motor is the engine, whilst a motor 
 car, autocar, or automobile, as it is sometimes called, is the 
 name for both carriage and motor. 
 
 2 It should be mentioned that some of the best makes 
 seldom, if ever, show any exhaust. 
 
 3 The obnoxious odor of the exhaust gases that so often 
 offend, is largely due to the condensation of gasolene vapor 
 which occurs before the engine, etc., is properly warmed up. 
 and to the volatilization of unsuitable lubricating oil used 
 in excess in the cylinders, or to its unsuitable quality. Refer 
 to articles 69 and 70.
 
 xii INTRODUCTION" 
 
 tances only steam and gasolene cars are at present avail- 
 able; and, for reasons which will be explained later, 
 comparatively few of the former are now running. 
 Thus the gasolene engine is used in the great majority 
 of cars now running, to say nothing of the enormous 
 and rapidly increasing number of motor bicycles now 
 in use, in which the motive power is the gasolene en- 
 gine. This doubtless accounts for the kind of motor 
 language that is heard at every turn, and, if the truth 
 must be known, by the boy in the school; for, strangely 
 enough, the schoolboy's allegiance to the locomotive has 
 been wavering in favor of the automobile for some time, 
 and now his school-locker generally contains a rare col- 
 lection of pictures, plates, post cards, technical journals, 
 and parts of models relating to autocars and motor 
 bicycles, instead of such things concerning the various 
 types of locomotives that were formerly so much in 
 favor; 1 indeed, it is often astonishing to see what an 
 amount of intelligent interest all kinds of people take 
 in the arrangement and working of motor vehicles. 
 This is particularly displayed whenever a car is stopped 
 in a public street, and its hood is lifted for a moment 
 or two; the usual crowd, which seems to spring from 
 the road itself, immediately surrounds the car, and 
 much advice, more or less pertinent, is freely offered, 
 and although the unhappy motorist may not profit 
 much by it, he cannot fail to be impressed with the 
 growing knowledge the "man in the street" has of 
 autocar matters. Of course, this knowledge is in most 
 cases very superficial and unsound, and requires to be 
 organized and supplemented by a good grasp, or at 
 least a rudimentary knowledge, of the principles which 
 underlie and govern the construction and working of 
 the motor, before it is of any practical use. So the 
 author, in arranging the articles in this little work, has 
 
 1 In this connection there cannot be a doubt that the great 
 progress we. are making in automobilism has had not a little 
 to do with the astonishing increase in the number of boys 
 whose greatest ambition is to become engineers.
 
 INTEODUCTION xiii 
 
 endeavored to explain in simple, and as far as possible 
 in non-technical, language the principles of construc- 
 tion and working that every potential motorist and 
 driver should be acquainted with before he attempts to 
 drive a car upon the road.
 
 MOTORS AND MOTORING 
 
 THE CHOICE OF A CAE 
 
 2. The matter of the selection of a car is one on which 
 it is practically impossible to give any adequate advice. 
 The prospective buyer, if he be wise, will have looked 
 over the field very carefully before he comes to a final 
 decision. Some idea of the range of power, price, and 
 kind of cars that are now upon the American market 
 may be formed by a study of the various periodicals de- 
 voted to the automobile sport and industry. At the 
 show in the Madison Square Garden at New York last 
 winter there were exhibited between two and three hun- 
 dred makes of American cars. The New York Import- 
 ers' Salon showed about fifty different designs. These 
 cars ranged from three and a half and four horse power 
 machines, costing $375, up to the forty, fifty, and 
 sixty and even ninety horse power cars, some of which 
 cost as high as $15,000. A pretty good idea of 
 price may be derived from the saying that a motor car 
 costs $100 a horse power and $1 a pound. There 
 are exceptions to this rule machines of sixteen and 
 eighteen horse power, quoted at under $1,000 but 
 it represents the average. Of the cars, American and 
 foreign, now on the market, ninety per cent, are pro- 
 pelled by the gasolene explosive engine. Makers seem 
 to be fairly evenly divided as to the merits of bevel and 
 chain driving. The desire for greater power has forced 
 most of the American makers to place on the market 
 four-cylinder cars, but these are of necessity compara- 
 tively high priced, and for light touring the two-cylinder 
 and single-cylinder cars are still satisfactory. The man 
 who knows what he wants, when he buys a car, will 
 usually be able to obtain reasonable concessions from
 
 2 MOTOKS AND MOTORING 
 
 the dealer. For instance, there may be a point or two 
 about which he is not absolutely satisfied. The make 
 of carburettor may not be to his liking, and he may ask 
 for one of another and higher grade. Few dealers will 
 be likely to let a matter of this kind prevent a sale. 
 
 ELEMENTS OF A MOTOR CAR 
 
 3. Every car, whether it be driven by electricity, 
 steam, or gasolene, consists of two principal parts, 
 namely,, the carriage body and the chassis.' 1 The for- 
 mer is practically complete in itself; the latter em- 
 bodies the following principal elements: the frame, to 
 which the motor proper and its accessories are attached 
 the transmission gear (including the chains in chain- 
 driven cars) axles, springs, road wheels, steering gear, 
 etc. 
 
 A complete car, with all its fittings and accessories, 
 appears to most novices a very complicated vehicle, but 
 when it is carefully examined, and the function of each 
 element and fitting understood, it really is often a 
 fairly simple machine; particularly is this so in cars 
 that have not been overloaded with refinements and 
 fittings of doubtful utility. It has frequently been 
 remarked that the general appearance of a car (with 
 the exception of an electric one) is often no sure indi- 
 cation of the arrangement of its component parts, or 
 the type of its motor, as makers have, with very few ex- 
 ceptions, adopted the outward form that everyone is 
 familiar with, and to accomplish this have even, in some 
 cases, put on dummy fittings and accessories. This ten- 
 dency is particularly noticeable where a characteristic 
 feature of some famous car is so imitated that at first 
 sight it is not easy even for an expert to name the 
 maker. It is a practice much to be deprecated, more 
 particularly as some of the designers who have thus 
 
 lr This French word has become Anglicized. ID France, 
 when strictly used, it means the frame only.
 
 MOTOKS AND MOTORING 3 
 
 sinned have produced cars of such excellence that they 
 should well be able to hold their own without such ad- 
 ventitious assistance. On the other hand, for obvious 
 reasons, there is much to be said in favor of co-ordinat- 
 ing in new cars, as far as is practicable, the driving fit- 
 tings and arrangements (more particularly the pedals 
 and brake levers), with those which are considered best 
 arranged on the leading cars. It will now be convenient 
 to give some detailed attention to the various elements 
 of the gasolene car, commencing with the motor. 
 
 THE GASOLENE MOTOR 
 Elements of the Complete Engine 
 
 4. As has been explained in footnote 1 to page xii, the 
 word motor, when strictly used, refers to the engine 
 which drives the car or cycle; but as the term is often 
 very loosely used, even by experts, who of course know 
 exactly what they are talking about and to what they 
 refer, it will be well to make clear that for our purpose 
 the gasolene motor will be considered to be the complete 
 working engine, one that could either be used to drive 
 a car, a boat, or any other machine, such as a lathe, 
 where power is to be transmitted to some rotating part. 
 That is to say, the motor must embody the engine 
 proper, and such auxiliaries as the carburettor, induc- 
 tion coil, accumulator, etc. The engine proper, as we 
 have called it, is diagrammatically represented by Figs. 
 2 to 5. It is often referred to as the Motor; so to be 
 clear on this point, before we further proceed, it must 
 be understood that when we use the word Motor the 
 complete system is referred to. Needless to say, this 
 explanation is given to prevent that confusion of 
 thought and meaning which too often hamper the prog- 
 ress of the tyro who is studying the internal economy of 
 the Motor Car. The first lesson in the art and pastime 
 of motoring might very appropriately be a brief descrip-
 
 4 MOTOBS AND MOTORING 
 
 tion of the Gasolene Motor, and to facilitate this the 
 author has made a diagrammatic sketch (Fig. 1) of 
 what may be called the complete system, which shows 
 the engine in relation to the subsidiary elements of the 
 complete motor. Obviously, the component parts are 
 arranged in such a way, in relation to one another, as to 
 show at a glance their interdependence, and enable the 
 beginner to get a grasp of the principles which govern 
 the working of the machine; this means that all the 
 parts must be arranged in the same plane, and some of 
 them made to appear larger than they would be if they 
 were drawn to scale. In other words, we have a dis- 
 torted sketch, showing the elements spread out for 
 ready inspection ; x and a careful examination of the 
 figure will enable the reader to become familiar with 
 the technical names of the most important elements, 
 details, etc., which will greatly assist him in under- 
 standing the description of the motor which is to 
 follow. 
 
 1 It should be hardly necessary to explain that for a fixed 
 position of the engine on the frame of the car, the auxiliary 
 elements of the motor can be fixed in an infinite number of 
 positions in relation to one another, so long as they are 
 connected up as shown in the figure.
 
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 MOTORS AND MOTORING 7 
 
 DESCRIPTION OF THE GASOLENE MOTOR 
 Or "Internal-Combustion Engine" 
 
 5. As has been explained, the motor, although an 
 element of the car, is a complete heat engine, consisting 
 of a number of elements ingeniously arranged in rela- 
 tion to one another to form a whole working machine, 
 in which the potential energy of the gasolene is con- 
 verted into moving energy at the crank-shaft (C.S., 
 Fig. 1). All gasolene engines in general use are recip- 
 rocating ones, that is to say, the straight line motion 
 of the piston (P., Fig. 1) is converted into the circular 
 motion of the crank-shaft by means of a connecting-rod 
 (C.R., Fig. 1) and crank (CK., Fig. 1). Now, every 
 single cylinder reciprocating engine must be fitted with 
 a fly-wheel, 1 fixed to the crank-shaft, to carry the crank 
 over the dead-center ; 2 but in the gas engine this wheel 
 has also another function to perform, which can better 
 be explained after we have made clear what goes on in 
 the cylinder during the engine's complete cycle. 
 
 THE OTTO CYCLE 
 
 6. The gasolene motor is an "internal-combustion 
 engine," that is to say, one in which a mixture of gaso- 
 lene vapor and air, automatically made in an element 
 called the carburettor (by the action of the engine), 
 in such proportions as to form an explosive mixture, is 
 drawn into the cylinder by the engine itself and elec- 
 trically ignited, causing combustion to occur, and the 
 
 'This wneel is not shown on the diagram; it generally 
 also forms the outer shell of the friction clutch. In cycle 
 motors the fly-wheel and crank are usually combined. 
 
 2 When the crank and connection rod come into the same 
 straight line, obviously no pressure on the piston, however 
 great, could cause the crank-shaft to turn, but by fixing a 
 fly-wheel to the crank-shaft, the momentum given to it 
 during the working stroke of the piston carries the crank 
 over the dead-center, as it is called.
 
 8 MOTORS AND MOTORING 
 
 piston to be pushed down with great force by the pres- 
 sure of the burning and expanding gases, this pressure 
 on the piston being transmitted through the connecting 
 rod to the crank-shaft. 
 
 The series of operations which take place in the 
 cylinder to form a complete cycle correspond to four 
 strokes of the piston and two revolutions of the crank- 
 shaft, and these operations make up what is called the 
 Otto cycle, after Dr. Otto, 1 who introduced it in 1876 
 in his " Silent " gas engine. 
 
 THE FOUR STROKES 
 
 An examination of Figs. 2 to 5 (which have been 
 drawn, with the positions of certain parts slightly 
 altered, so that each essential detail can be seen quite 
 distinctly, to conveniently illustrate this description) 
 will enable the reader to be clear about what occurs 
 during each stroke. 
 
 1st. The Suction or Charging Stroke (Fig. 2). 
 During the first out-stroke of the piston a partial 
 vacuum is formed, and, the piston acting as a pump, the 
 explosive mixture is drawn into the cylinder through 
 the inlet valve, the spring of which is only sufficiently 
 strong to hold up the valve on its seat. 
 
 2nd. The Compression Stroke (Fig. 3). During the 
 return or in-stroke, both the inlet and exhaust valves 
 are closed, and the explosive mixture, which was drawn 
 in during the previous stroke, is compressed by the 
 piston into the clearance space (or combustion cham- 
 ber). 
 
 1 The four-stroke cycle was first suggested by Beau de 
 Rochas in 1862, but the gas engine invented by Dr. Otto, 
 and made by Crossley Brothers, first established the econ- 
 omy and efficiency of internal-combustion engines working 
 on this cycle. The invention was the subject of a patent 
 granted in 1876, No. 2081, to C. D. Abel, for improvements 
 in gas motor engines (a communication from abroad by 
 N. A. Otto).
 
 THE GASOLENE- ENGINE 
 DIAGRAMMATIC DRAWINGS SHOWING THE FOUR STROKES OF THE 
 
 Fig. 2. 
 
 OTTO CYCLE. 
 
 iHtET VALVE OPENED TOExPLOSIVEMlXTURt BOTH VALVES CLOSED OURINd 
 
 BY SUCTION. 
 
 COMPRESSION 
 
 TV EXHAUST STROKE 
 
 Fig, 5.
 
 10 MOTORS AND MOTORING 
 
 3rd. The Explosion and Expansion Stroke (Fig. 4). 
 The compressed charge is ignited by an electric spark 
 (or an incandescent tube 1 ) after the crank has just 
 passed the dead-center; and the pressure, due to the 
 heat energy, developed by the combustion, so rapidly 
 rises that, before the piston has appreciably moved on 
 this second forward or working stroke, it reaches its 
 maximum, and work is done on the piston by the 
 expanding gases. 
 
 4th. The Exhaust Stroke (Fig. 5). When the piston 
 has traveled about four-fifths 2 of its working stroke, 
 the exhaust valve is opened by the cam on the two-to-one 
 shaft 3 to reduce the back pressure (or give release) ; 
 the exhaust taking place during this fourth stroke of 
 the cycle, or second return or in-stroke; the products of 
 combustion being discharged from the cylinder, the 
 gases which remain in the clearance space (or combus- 
 tion chamber) mingling with the incoming explosive 
 mixture of the next charge. 
 
 Thus, it will be seen that the clearance space (Fig. 2) 
 is filled with the products of combustion at about atmos- 
 pheric pressure when we commence to trace the work- 
 ing of the engine; and the piston, whilst it compresses 
 the explosive mixture and makes the other strokes, with 
 the exception of the explosion one (the third), is driven 
 by the energy stored in the rotating fly-wheel. 
 
 Strangely enough, this method of working (the Otto 
 Cycle) has never been equaled in efficiency by any 
 other the mechanical genius of the world has been 
 able to devise. Up to the time of its introduction, gas 
 engines were worked by drawing in the charge during 
 
 1 Refer to Article 26 for information. 
 
 *The time of opening the valve should vary with the 
 piston speed, being earlier the higher the speed. 
 
 8 This shaft is shown in Fig. 1. It is connected with the 
 crank-shaft by a system of tooth wheels, which make the 
 cam-shaft rotate once, whilst the motor-shaft rotates twice ; 
 thus the exhaust valve opens once during every two rota- 
 tions of the crank-shaft
 
 MOTORS AJsD MOTORING 11 
 
 the first portion of the stroke, and then firing it, the 
 work being performed during the remaining portion of 
 the stroke * ; but the real and fundamental improve- 
 ment made by Otto was the compressing of the con- 
 tents of the cylinder (the explosive mixture) into the 
 clearance space at the end before the charge was fired. 
 This cycle of operations was new and original, and 
 was founded upon true mechanical principles. The 
 mode of working is not only admirable when examined 
 from a mechanical point of view, but there is also 
 the positive and direct gain of dealing with a com- 
 pressed charge, instead of one at atmospheric pres- 
 sure 2 (the engine acting as its own compressing 
 pump) ; for the advantage of being able to start at the 
 instant of explosion with the compressed contents of 
 a whole cylinder full of explosive mixture, instead of 
 the uncompressed contents of half a cylinder, is evident 
 to ordinary apprehension. Then it is also claimed that 
 the residue of the products of combustion remaining 
 in the cylinder (the contents of the clearance space) 
 acts as a cushion to moderate the effect of the explosion 
 upon the working piston. 3 
 
 If we are to maintain, in explaining matters, some- 
 thing approaching a sequence, it will be convenient to 
 now give a little attention to the valves of the engines. 
 
 VALVES 
 
 7. In the previous article we have explained how the 
 inlet or induction valve (called automatic inlet valve, 
 
 1 The Lenoir engine, patented 8th February, 1860. 
 
 * In recent years there has been a marked increase in the 
 pressure to which the charge is compressed in gas engines, 
 with a corresponding increase of efficiency. 
 
 3 There is much to be said for and against this practice. 
 A fresh mixture of gasolene vapor and air does not easily 
 mix with the burnt gases ; probably stratification more or 
 less occurs. We shall further touch upon this matter in 
 connection with governing.
 
 12 MOTORS AND MOTORING 
 
 and abbreviated to A.I.V.) is automatically opened by 
 the suction action of the piston in the first stroke, 
 being just kept on its seat at other times by the action 
 of a weak spring ; x on the other hand, we have seen 
 that the exhaust valve was mechanically operated or 
 lifted by a cam fixed on the half-speed or two-to-one 
 shaft, the valve being spring closed. Now the auto- 
 matic working of the inlet valve, although simple, and, 
 under ordinary conditions of working, very effective, 
 is not scientifically sound, particularly for high speeds, 
 as the clearance space at the commencement of the first 
 stroke is full of the burnt gases above atmospheric 
 pressure, due to the back pressure from the silencer; 
 therefore, when the piston begins its suction stroke, 
 these gases have to expand before the fresh mixture 
 can be drawn in by the piston ; hence the sluggish action 
 of the valve in opening, just when it should be 
 promptly responding to the invitation to move given 
 by the piston when it commences its stroke; indeed, 
 in high-speed motors the valve should have a slight 
 lead that is, should open just before the commence- 
 ment of the stroke, thereby facilitating the scavenging 2 
 
 1 This spring must be perfectly adjusted, for correct work- 
 ing. If too weak, the valve will not close rapidly enough to 
 prevent the escape of explosive mixture on the commence- 
 ment of the compression stroke, and will subsequently close 
 with violent impact on its seat ; with such a spring the 
 motor might be run very slowly, but it would be qiiite use- 
 less for high speeds. On the other hand, if the spring be 
 too strong, it does not allow the valve to open readily 
 enough, or to its full extent, to allow a full charge of mix- 
 ture to enter, and the power of the motor is therefore 
 reduced. A common practice is to arrange the spring so 
 that an air pressure of one pound per square inch will 
 open it, but to get the best results the tension of the spring 
 should be made adjustable. Spare springs are usually sup- 
 plied long enough to allow them to be cut away bit by bit 
 till the valve closes with a light beat. 
 
 2 Sweeping out some of the residual burnt gases from the 
 previous charge, and thereby allowing a greater quantity 
 of mixture to enter the cylinder every charge, and in so 
 doing increasing the power of the engines.
 
 MOTORS AND MOTORING 13 
 
 of the combustion chambers (clearance space). More- 
 over, the effect of the inertia of the valve becomes more 
 pronounced as the speed of the engine increases, and 
 the volume of intake suffers, whilst the metallic noise 
 of the valve beating on its seat is objectionable. So, 
 primarily for these reasons, makers have for some time, 
 in increasing numbers, been fitting motors with me- 
 chanical operated inlet valves (abbreviated to M.O. 
 I.V.), or worked in the same way as the exhaust valves 
 from a half-speed shaft. 1 This enables the time of 
 opening and closing of the valve to be arranged with 
 mathematical precision, and (should it be thought 
 desirable) the valve to remain open a shade after the 
 piston commences the compression stroke, so that the 
 momentum of the entering mixture may slightly add 
 to the charge, before the piston on its change of stroke 
 has converted the slight vacuum in the cylinder to a 
 pressure above atmospheric. 
 
 In strictly examining the relative merits of these two 
 arrangements, we ought to take into account the effi- 
 ciency of the carburettor that is used in conjunction 
 with each; but for our present purpose it will suffice 
 to point out that in the M.O.I.V. a continuous flow of 
 mixture can be relied upon for a definite movement of 
 the piston, if the carburettor is capable of satisfactorily 
 carburetting a sufficient quantity of air to keep pace 
 with the protracted draw upon it, due to the longer 
 time the valve remains open, as compared with an 
 automatic one, for the latter cannot leave its seat till 
 the vacuum in the cylinder is good enough to cause the 
 spring to extend; the valve then suddenly opens, when 
 a considerable inrush of mixture occurs, but the valve 
 does not remain unclosed during the completion of the 
 suction stroke, but rapidly flutters or pulsates on and 
 off the seat (in a way everyone can understand who is 
 familiar with the behavior of springs) till the end 
 
 1 In some motors the same shaft operates both valves, 
 but the more general arrangement is a separate shaft each 
 side of the engine.
 
 14 MOTOES AND MOTORING 
 
 of the stroke is reached ; * consequently the demand on 
 the carburettor is intermittent, and therefore less 
 exhausting than in the other case. 
 
 Makers have from time to time, in acceding to the 
 demand for mechanically operated valves, met with a 
 good deal of trouble before they have reached satisfac- 
 tory results; but the conditions which must be satisfied 
 are so well understood now, that there is no difficulty 
 in producing engines fitted with mechanically operated 
 valves that are highly efficient, and are connected to 
 carburettors adapted to their peculiar needs. Such 
 valves are made interchangeable with the exhaust 
 valves; they never stick or become sluggish in working 
 through oil or other foreign matter clogging the valve 
 or its stem, and with them the engine at slow speeds 
 is more easily controlled, their use involving a mere 
 repetition of the cam gear required for the exhaust 
 valve. 
 
 Of course this slight complication is not in their 
 favor, but in the best cars the design and workmanship 
 are so excellent that they give no trouble; indeed, this 
 is a case where some sacrifice of simplicity can be 
 safely made for increased efficiency and flexibility. 2 
 
 8. Leaky Valves. A fruitful source of trouble and 
 loss of efficiency in the gasolene motor is leaky valves. 
 The burning and erosive effect of the hot gases (par- 
 ticularly if an exhaust valve has been held off its seat 
 by dirt), and hammering of valves on their seats, must 
 sooner or later lead to a sensible amount of wear occur- 
 ring, both on valves and seats, even when the materials 
 are just as perfect as it is possible to make them; but 
 this legitimate wear is greatly increased in cases where 
 the materials are too soft, or are in some other respects 
 unsuitable. Of course, if this wear took place with 
 
 a This action causes the actual working area to be only 
 about half what it would be if the opening remained con- 
 stant, so that the A.I.V. is larger than a M.O.I.V. 
 
 2 Some engineers, whose opinions are entitled to respect, 
 prefer, on the whole, the A.I.V.
 
 MOTOKS AND MOTOKING 15 
 
 absolute uniformity, without the surface departing from 
 its true form, there is no reason why leakage should 
 occur, but in practice, after a certain amount of wear, 
 all valves leak, it being only a matter of degree ; indeed, 
 should the power of the motor diminish, and there is 
 reason to suppose that it is due to leaky valves, the 
 valves should be examined, and if there is any doubt 
 about an inlet one, the spare valve (which should 
 always be carried as part of the equipment) should be 
 put in to replace it, and the old one can be examined 
 and reground, if necessary, at home. The effect of 
 leaky valves is at once felt, as during the compression 
 stroke the mixture is forced through them, so that there 
 is a smaller charge, and a full pressure cannot be 
 reached. 
 
 9. Grinding in Valves is an operation that had better 
 be left to the trained mechanic to perform, but cases 
 occasionally occur where one is not available, and many 
 owners of cars like to be able to do these little jobs 
 themselves, or at any rate to know how they are done. 
 So a few words relating to them will not be out of 
 place. Now, if the valve is merely inclined to stick, it 
 should be well washed out with gasolene, which will clear 
 it of any bad oil or dirt. If, on the other hand, it 
 requires grinding, it will be found that the conical or 
 mush-room valve has a groove cut on its upper part to 
 fit a screw-driver, or screw-driver bit that can be worked 
 with a drill brace. The grinding material is a paste 
 made of oil and fine sharp emery powder, 1 and the seat 
 of the valve should be smeared with this, and the valve 
 turned to and fro on its seat with the screw-driver or 
 brace, being taken off occasionally and the face re- 
 smeared to prevent grooving. This tedious operation 
 must be continued until both surfaces present a bright 
 and even appearance, without inequalities past which 
 gas could escape. A piece of cotton waste should be 
 
 1 Meteoric Knife Polish is a preparation of emery powder, 
 and will do.
 
 16 MOTOKS AND MOTOEING 
 
 carefully placed to prevent any of the powder or dirt 
 getting into the cylinder. 
 
 10. Valve Lifter. To enable a motor bicycle to be 
 freely pushed along or pedaled when the engine is not 
 working, it is necessary to open the exhaust valve to 
 prevent the motor being converted into an air-compres- 
 sor, for, obviously, a good deal of work would have to be 
 done by the cyclist on the machine in giving motion 
 to the piston during the compression stroke. 1 So, to 
 obviate this, motor bicycles are fitted with a device 
 called a Valve Lifter, by means of which the exhaust 
 valve may be kept permanently lifted at the driver's 
 will. This fitting enables him to start the engine by 
 walking the bicycle and suddenly letting go the lifter 
 after the fly-wheel has had given to it enough mo- 
 mentum to perform the compression stroke. Skillful 
 use of this lifter when on down grades will have a 
 cooling effect on the cylinder (which often tends to 
 become too hot for satisfactory working), cool air 2 
 being drawn into the cylinder through the exhaust pipe 
 from the muffler each two revolutions of the engine. 
 The only objection to this convenient expedient is, that 
 the air in passing through the muffler tends to carry 
 with it any dirt or dust that may be in it. 
 
 When using the lifter, care must be taken to cut off 
 the spark, or explosions will occur in the muffler. 
 
 We may now proceed to describe the nature of the 
 explosive mixture, and how it is produced ready for 
 use in the cylinder. 
 
 CARBURATION AND CARBURETTORS 
 
 11. If the odor of escaping gas be detected in a house, 
 
 'Of course, the whole of this work is not lost, as some 
 of it is recovered during expansion. 
 
 2 After the engine has been running the muffler becomes 
 very hot, and therefore the first few charges of air which 
 pass into the cylinder when the lifter is used are warmer 
 than the outside air.
 
 MOTOES AND MOTOKING 17 
 
 it is proverbial that the ordinary householder will seek 
 for the leak with a lighted candle, too often with a 
 result that everyone has heard of and no one seems to 
 profit by. In such cases the escaping gas mingles with 
 the air in the room and carburates 1 it, as it is called; 
 that is to say, the carbon and hydrogen of the gas, of 
 which it nearly wholly consists, become rapidly dif- 
 fused in the air, the oxygen of which forms, or tends to 
 form, with the hydrocarbon gas, an explosive mixture 
 which only requires igniting to cause an accident. 2 
 
 Now the explosive mixture we use in the gasolene 
 motor consists of air carburetted by the vapor of gaso- 
 lene, 3 and the apparatus used to prepare or form this 
 mixture is called a carburettor, a fitting that appears 
 in a great variety of forms; indeed, a month rarely 
 passes without the pages of our admirable motor jour- 
 nals being adorned with some new device, which more 
 or less differs from existing ones. There is nothing 
 astonishing about this when it is understood how easily 
 a mixture can be made, for everyone has noticed how 
 quickly a little Eau de Cologne vaporizes when applied 
 to the hands or face. The same thing occurs with 
 gasolene; it is an exceedingly volatile spirit, rapidly 
 evaporating, as all spirits do when exposed to the air, 
 and this action is much increased by the application 
 of heat, but it does not require any preliminary heating 
 
 1 When air is impregnated with carbon, it is said to be 
 carburetted or carburized. 
 
 2 It is instructive to note that a mixture of this kind may 
 be either too weak or too strong to explode, as for complete 
 combustion about 6.3 volumes of air to 1 of gas are required ; 
 but the range of ignition appears to be about 1 of gas to 5 
 of air, to 1 of gas to 13 of air. And so, in the cylinder of 
 the motor, we may have a charge which consists of too 
 much air, or, the more usual case, one that has been super- 
 carburetted (one that is too rich in gasolene vapor). 
 Between these extremes there is a particular or critical 
 mixture that in any case will be more efficient than any 
 other, as we shall directly see. 
 
 3 Gasolene is a hydrocarbon. Refer to article on fuel, 
 page 28.
 
 18 MOTOES AND MOTOKING 
 
 for use in even the smallest engines. It can be readily 
 vaporized by the simplest and crudest form of car- 
 burettor, and this principally accounts for the wonder- 
 ful flexibility of the gasolene motor; indeed, it now 
 appears difficult to make a motor that won't go, 
 although a few years ago, when so many were com- 
 mencing to experiment with motors who were unac- 
 quainted with matters relating to carburation and 
 ignition, much trouble was experienced in coaxing them 
 into motion. 
 
 If an explosive mixture can be readily produced, it is 
 not such an easy matter to satisfy all the important 
 conditions, for a satisfactory carburettor * must be capa- 
 ble of regularly supplying a perfectly adjusted mixture 
 of gasolene vapor (or atomized spray) and air to the 
 motor cylinder under all conditions of speed, load, and 
 temperature ; it must be, self-adapting, and be able to 
 automatically and definitely carburet the air to form 
 a mixture of an exactly predetermined degree under 
 all conditions of working. The very perfect speed con- 
 trol, over a wide range, of some of the best known 
 motors is largely due to these conditions being more or 
 less satisfied, and to a well-governed throttle 2 and an 
 adjustable ignition. 3 
 
 12. The Float-Feed Carburettor. The type of car- 
 burettor that has survived all others, owing to its sim- 
 plicity and absolute automatic action, is the float-feed 
 one or spray kind, shown in Fig. 6, which shows the 
 principal features of the class of carburettor to which 
 it belongs. An atomizing nozzle N (whose size is care- 
 
 1 Most carburettors on large cars are fitted with hot 
 jackets for use in cold weather, as will be explained, the 
 heat of the engine itself sufficing in other cases. 
 
 2 When a motor is governed by throttling or reducing the 
 quantity of the charge of the explosive mixture, without 
 altering the proportions of air and vapor, it is said to be 
 governed on the throttle. Refer to article on governing 
 and controlling by throttling the mixture, page 55. 
 
 8 Refer to article on Advancing and Retarding Ignition, 
 page 50.
 
 MOTOES AND MOTORING 
 
 19 
 
 fully calculated) is supplied with petrol from the float- 
 chamber FC, into which the spirit (gasolene) flows 
 by gravitation from its tank through the pipe X, and 
 is kept at a constant level by a float FF, the needle 
 
 FLOAT-FEED CARBURETTOR. 
 
 valve V regulating its flow; thus the gasolene is drawn 
 from the float-chamber through an exceedingly fine 
 orifice in the nozzle N, in the form of a spray, into the 
 mixing chamber MM (pulverization being assisted by 
 it impinging upon the roughened surface of the fixed 
 cone K and becoming atomized), where it is carburized 
 by mingling with the air from the inlet AV on its way
 
 20 MOTOES AND MOTORING 
 
 to the cylinder, the mixture being drawn through the 
 throttle valve T (as it passes to the inlet valve of the 
 engine) by the suction stroke of the piston. Vaporiza- 
 tion of the atomized spray in the mixing chamber MM 
 is assisted by the hot jacket J, which is heated by pass- 
 ing through it (entering at E and passing out at 0) 
 either hot water from the cylinder jacket or exhaust 
 
 The richness of the mixture is regulated either by 
 controlling the quantity of the gasolene passing through 
 the nozzle N, or the quantity of air entering the mouth 
 AV; if by the former, a valve G, operated by a hand 
 wheel W, varies the size of the passage through which 
 the gasolene flows on its way to the nozzle N ; and, if by 
 the latter, a shutter AV fitted with a sheet of gauze to 
 prevent any fluffy matter passing (regulated by the fly 
 nuts RE, the stay S being fixed), controls the quantity 
 of air entering. This adjustment is made before start- 
 ing on a run, to suit the condition of the atmosphere; 
 the quantiy of air required to make the best mixture 
 varying with its temperature and pressure, it frequently 
 happens that on a hot day the mixture will require 
 readjusting in the cool of the evening. Now to keep 
 the quantity of mixture constant, and to ensure the 
 
 l The well-known Longuemarre carburettor is heated by 
 the exhaust gas. In either case, the flo^ of fluid through 
 the jacket should be regulated by a cock or plug, as when 
 too cold, the gasolene does not volatilize sufficiently, and 
 when too hot it does so to excess. As a matter of fact, it 
 is only when the atmosphere is heavily charged with moist- 
 ure, or when running through keen, frosty air, that a heat- 
 ing jacket is required; if such means for regulating the 
 temperature of the jacket are not provided, the resultant 
 cylinder charge is often much richer than is necessary or 
 good for the engine, causing the plugs and valves to become 
 sooty. When a hot jacket is not used on a carburettor, it 
 is usual to so fix the latter that the air mouth is near 
 enough the cylinder for the air entering the carburettor 
 to be previously warmed ; indeed, long, cold pipes should 
 never be used to convey the mixture from the carburettors 
 to the cylinder, as the gasolene vapor in the mixture is 
 apt to condense when reduced in temperature.
 
 MOTORS AND MOTORING 21 
 
 opening of gasolene valve G and air-shutter AV, the level 
 of the gasolene in the float-chamber FC must be unvary- 
 ing, and this condition is satisfied by the action of the 
 float 1 FF and needle, for should the level of the spirit 
 slightly fall, the float FF and attached needle would 
 descend with it, allowing the weights WW to operate 
 the levers WH, whose fulcra are at HTL This move- 
 ment causes the other ends of the levers to move up- 
 wards and carry with them the grooved collar on the 
 needle, into which they fit; this lifts the needle point 
 off its seat and allows more gasolene to pass from the 
 tank to the float-chamber; this in its turn lifts the float 
 and depresses the needle closing the valve, so that the 
 float automatically maintains the level of the gasolene. 
 Great care must be taken to pass the spirit through a 
 strainer in filling the tank. In the best arrangements 
 a screen of fine gauze is placed, as at Q, to exclude any 
 dirt which may be in the gasolene, which, if allowed 
 to enter, would tend to stop up the small passages, and 
 prevent the flow of gasolene; indeed, such stoppages are 
 a fruitful source of trouble, particularly at the nozzle, 
 where dust, carried in by the air, is apt to give trouble. 2 
 Should the screwed bung which is generally used to 
 stop the filling-hole in the gasolene tank get lost, it 
 should never be replaced by a cork one, as cork-dust 
 sooner or later will find its way into the carburettor, 
 and cause endless trouble by blocking the small pas- 
 
 13. Auxiliary Air. It would be interesting and in- 
 
 1 If great care is not taken to make the float perfectly 
 fluid tight, the gasolene will penetrate it and cause it to 
 be " water-logged," as it is called ; it then, of course, ceases 
 to act as a float. 
 
 2 The usual expedient in this case, if time will not admit 
 of the carburettor being properly cleaned, is to push a 
 piece of fine wire through the hole and twirl it round ; this 
 invariably answers the purpose, but tends to enlarge the 
 hole and make the mixture too rich ; so, to be on the safe 
 side, carburettors should be periodically taken apart and 
 thoroughly cleaned.
 
 22 MOTOES AND MOTOKING 
 
 structive to go into all the points which must be con- 
 sidered in deciding how the degree of carburation 
 should vary with different temperatures, atmospheric 
 pressures, speeds and other conditions of running, but 
 space will not admit of this, and it must suffice to point 
 out that the practice, which is found to give excellent 
 results with this type of carburettor in maintaining 
 a uniform mixture, is to admit what is called auxiliary 
 air to the mixing chamber (to mingle with the mixture 
 and reduce its richness), when the engine is running 
 fast and the vacuum is good. The air is admitted 
 through the auxiliary air-valve AAV, which is fitted 
 with an adjustable spring Z (so that its strength may 
 be adjusted to give the best results), and when the 
 suction is strong enough, this valve is forced open by 
 the air outside, against the action of the spring, and 
 extra air flows in and mingles with the mixture. Now, 
 let us try and be clear why this extra air is required. 1 
 To do this, we must realize that during a rapid suction 
 stroke, air and gasolene are being drawn through the 
 openings AV and nozzle N respectively, at a high 
 velocity; at the end of the stroke the inlet valve of the 
 engine cylinder suddenly closes, and no further mix- 
 ture can enter. This means that the flow of air through 
 AV almost immediately stops; but not so the gasolene, 
 as, due to its much greater density and inertia, it con- 
 tinues to flow into the mixing chamber M, and would 
 make the mixture much too rich to give a good result 
 in the cylinder were it not for the extra air entering 
 by the auxiliary valve. Again, as the engine slows 
 down, let us say, due to throttling (partly closing the 
 throttle valve T), there is a greatly reduced suction 
 (not enough to open the auxiliary air-valve), and 
 although air may be freely entering at AV, the gasolene 
 will be passing out of nozzle N in a very sluggish way, 
 
 x ln some carburettors, instead of admitting air by an 
 auxiliary valve, it is passed into tbe mixing chamber by 
 increasing the opening of the air inlet at AV by a control 
 arrangement.
 
 MOTORS AND MOTORING 23 
 
 and there will be an abundance of air in the chamber 
 to form a proper mixture, until at a critical speed 
 of the engine the suction will not be strong enough 
 to draw gasolene out of the nozzle, as the normal level 
 of the spirit in the nozzle must always be a little below 
 the orifice; but this speed of course the motorist soon 
 becomes familiar with, and he is careful to avoid touch- 
 ing it if he wishes to keep the motor running. 
 
 Formerly (in the days of the old cut-out governor) 
 it was not practicable to vary the speed of the engine 
 very much, but with the introduction of the throttle 
 control x which has been so generally adopted, a great 
 amount of elasticity or flexibility in running became 
 possible, and now most engines have a range from about 
 200, or even 150 revolutions per minute when throttled, 
 to 1500 or 1600 in some cases when the throttle is fully 
 open, the amount of mixture used being almost in pro- 
 portion to the speed. 
 
 In many of the carburettors in use (notably Kreb's), 
 great ingenuity has been displayed in devising them, so 
 that the fundamental condition for perfect working 
 may be automatically satisfied, namely, the production 
 of a constant degree of carburation at all speeds, so 
 that the power of the motor may be directly propor- 
 tional to its speed. In those carburettors that are not 
 fitted with such an automatic arrangement, the mix- 
 ture must be made by hand. In any case, the adjust- 
 ment should be made to enable the carburettor to take 
 in as much air as it possibly can whilst producing a 
 good mixture, as a faulty mixture is nearly always due 
 to an extravagant and wasteful use of gasolene, with 
 all the evils attending it. 2 
 
 The spray type of carburettor, largely owing to its 
 compactness and the small amount of room it takes 
 up, is also superseding the float type for motor cycles, 
 
 1 By the governor ; or the amount of mixture entering the 
 cylinder may be controlled by hand. 
 
 2 Generation of steam in the cylinder jacket, sooty plugs, 
 loss of power, and waste of fuel.
 
 24 MOTORS AND MOTORING 
 
 although it has the disadvantage of being easily flooded 
 when the machine is run over a rough road, the jolting 
 allowing the gasolene to escape into the reservoir each 
 time the needle is bumped off its seat; as a result, the 
 gasolene supply-pipe has to be fitted with a small cock 
 or valve, so that the quantity flowing can be regulated 
 by hand when necessary. 
 
 In starting, it is sometimes necessary (owing to the 
 nozzle becoming more or less closed by dirt, and the 
 gasolene in it becoming stale 1 by standing) to flood the 
 carburettor and to assist in forming a rich mixture by 
 spraying the spirit by hand; to do this, the thimble B 
 (Fig. 6) is taken off, and the end U of the valve spin- 
 dle moved up and down, an upward movement allowing 
 the gasolene to enter the float-chamber from the tank, 
 and a push downwards forcing it through the nozzle. 
 
 14. Surface Carburettors. The carburettors that 
 were first generally adopted, and are still used on some 
 motor cycles, were of the surface type, an example of 
 which, of the pattern used on motor tricycles, 2 namely 
 the De Dion, is shown in Fig. 7. Outwardly it consists 
 of a triangular brass or copper box, shaped to fit be- 
 tween the tricycle frame tubes and the rider's seat. In 
 the figure, one side has been removed to show the ar- 
 rangement of the interior; a plate D, fixed to the air- 
 tube or chimney AT, divides the whole box into two 
 parts, the lower forming a reservoir for the gasolene, a 
 further quantity of which is generally carried in a cylin- 
 
 1 Gasolene, when allowed to stand exposed to the air, 
 rapidly evaporates, the most volatile part passing off first, 
 the portion remaining being impoverished or stale. 
 
 'The principle of the surface carburettor can be best 
 understood by examining this pattern. Those used on bicy- 
 cles are very much alike in principle and general con- 
 struction. In a pattern largely used the air-tube AT is 
 carried down nearly to the bottom of the reservoir R, and 
 its lower part is perforated or zig-zagged, so that the air 
 bubbles up through the spirit instead of skimming its sur- 
 face, and with this arrangement almost the last drop can 
 be used, even if it is a little stale.
 
 MOTORS AND MOTORING 25 
 
 drical tank attached to the rear frame of the machine, 
 and placed just above and connected to the carburettor 
 by a pipe. The plate D is used to prevent the spirit 
 splashing into the upper chamber X in the form of 
 spray, instead of passing into it as vapor. The air 
 enters through the air-tube AT, and passes between the 
 
 THE DE DION SURFACE CARBURETTOR. 
 X 
 
 Fig. 7. 
 
 plate D and the gasolene surface (which in starting is 
 just below the plate) as shown, licking the surface, and 
 carrying with it a charge of spirit vapor to the cham- 
 ber X, on its way to the mixing chamber or twin tap, 
 MC. The function of the tube AT is to admit air below
 
 26 MOTORS AND MOTORING 
 
 the plate D during the suction stroke of the engine, 1 so 
 that it may be diffused in the gasolene vapor, as ex- 
 plained, and be drawn through the twin tap MC, which 
 is arranged to admit an adjustable quantity of addi- 
 tional air to form a suitable mixture to enter the cylin- 
 der through the pipe M. A bent pipe, LN, from the 
 engine exhaust passes through the lower part of the 
 reservoir to warm the gasolene, and to accelerate its 
 vaporation, as evaporation of the spirit lowers its tem- 
 perature. F is a float fixed to a wire EF, which passes 
 through the air-tube AT, the length of the wire at E 
 projecting above AT indicating the level of the gaso- 
 lene in the reservoir. The most interesting and impor- 
 tant feature of this type is the twin tap MC, shown in 
 detail in Figs. 8, 9, and 10, the Fig. 8 showing a section 
 on line XX (Fig. 7), and Figs. 9 and 10 being sections 
 taken through the lines DD and EE (Fig. 8) respec- 
 tively. These show how the air lever A is connected to 
 a hollow cylindrical part, a half of it, MON, being made 
 of wire gauze, in such a way that a movement of lever 
 A controls the quantity of rich mixture entering below 
 at K from the chamber H, and the amount of auxiliary 
 air passing in from above at J, the two streams mixing 
 in the chamber P to form the perfected mixture, which 
 passes into the pipe M on its way to the cylinder. A 
 movement of the lever A (Fig. 10) to the right increas- 
 ing the opening for air, and decreasing the opening VN 
 for the rich mixture, so that the quality of the mixture 
 can be regulated when starting to give the best results 
 for the gasolene used, and the temperature, pressure, 
 and condition of the atmosphere. 
 
 The Figs. 8 and 9 show how the gas lever G moves 
 the hollow cylinder WY, which is free to revolve in the 
 outer cylindrical case, so that it acts as a throttle valve, 
 giving the rider control over the quantity of mixture 
 which passes into pipe M from the mixing chamber P 
 on its way to the cylinder. 
 
 a The cap on top of AT forms an adjustable shutter, used 
 to regulate the quantity of air entering.
 
 MOTORS AND MOTORING 27 
 
 One of the drawbacks of this carburettor is that it 
 takes up more room than the spray one, and it cannot 
 
 I 
 
 be used with such heavy gasolene as the latter can. On 
 the other hand, it has some advantages which perhaps
 
 28 MOTORS AND MOTORING 
 
 have not always been appreciated as they should be for 
 small engines, particularly for motor bicycles. Not the 
 least of these is, it has no very small gasolene holes to 
 get clogged with dirt, and throttling does not affect the 
 carburation, as it does in many of the simplified spray 
 carburettors, leading to excessive gasolene consumption. 
 
 THE FUEL 
 
 15. The fuel that is almost exclusively used by mo- 
 torists in this country is the light petroleum spirit, 
 called gasolene. It possesses valuable properties, which, 
 notwithstanding its drawbacks, make it at present con- 
 sidered the most suitable fuel for motor purposes. It 
 is a distillate of crude petroleum, the various products 
 of which (called fractions or cuts) are obtained by 
 what is known as fractional distillation. 
 
 16. Straining and Filtering Gasolene. Compara- 
 tively few motorists realize the necessity of carefully 
 straining the gasolene as it is poured into the supply- 
 tank of the car. If they commence by using a strainer, 
 sooner or later it will become mislaid, and the spirit is 
 poured into the tank direct from the can ; in doing this, 
 they risk getting an accumulation of dirt in the tank, 
 which in due course finds its way into the carburettor, 
 with the inevitable stoppage, for, even if the carburettor 
 it fitted with a disc of gauze within the union below 
 the float-chamber, as shown at Q in Fig. 6, it is only a 
 matter of time for its minute interstices to become com- 
 pletely filled, and the flow of gasolene to be stopped, so, 
 should the strainer become mislaid, one should be im- 
 provised. For instance, a clean handkerchief folded 
 three or four times has been found to be an effective 
 substitute. Many motorists have been troubled by a 
 kind of short silky fluff getting into the union below 
 the float-chamber; this stuff is much too fine to be ar- 
 rested by the gauze, so something with a much finer 
 mesh is required for the strainer; a good-sized piece of
 
 MOTOES AND MOTOBITO 29 
 
 clean thin chamois-skin has been found effectually to 
 filter the spirit without unduly delaying the filling of 
 the tank; of course this necessitates the use of a funnel 
 of large diameter, say some 8 or 9 inches at least. 
 
 GASOLENE, ITS DISADVANTAGES, AND THE 
 PBECATJTIONS TO BE TAKEN IN USING IT 
 
 17. No one should be entrusted with a can of gaso- 
 lene who is unacquainted with some of its properties; 
 every motorist should make a point of learning what 
 liberties he may and may not take with it. It being a 
 highly volatile spirit, a naked light or ordinary lamp 
 should never be taken into a place where it is. stored, or 
 into a motor-house; nor should smoking be allowed in 
 such places, as a slight leak would probably lead to an 
 accumulation of gasolene vapor, which would be highly 
 dangerous. On the other hand, leakage of gasolene on 
 a moving car would cause no more danger from explo- 
 sion than a gas jet escaping for a few minutes in the 
 open air, but a fairly large quantity of gasolene spilled 
 in the street or in a room would be a cause of danger 
 from its vapor mixing with the air and forming an ex- 
 plosive mixture, through which a flame could leap sev- 
 eral feet. Gasolene spirit itself merely ignites with a 
 hot flame, and does not cause an explosion; indeed, a 
 poker almost red-hot may be placed in gasolene without 
 its igniting, although a white-hot one would cause it to 
 burn; but when gasolene vapor mixes with about 8 to 
 10 times its volume of air, a rich gas is formed, which 
 will burn without exploding; a larger proportion of air, 
 about 17 or 20 to 1, forms an explosive mixture. 
 Finally, it is dangerous for transport or storage, and 
 the risk is greatly increased in a hot climate, owing to 
 its low flash-point, as any oil is dangerous when heated 
 above its flashing-point, be that high or low. Of course 
 the ideal light for the motor-house is the electric light,
 
 30 MOTOKS AND MOTOEING 
 
 but when this is not available a Davy lamp 1 should 
 always be used when gasolene is under cover, to avoid 
 risks, as the conditions necessary for an explosion should 
 be assumed to always exist. 
 
 18. Objectionable Odor of the Exhaust Gases. The 
 offensive odor of the exhaust gases, from most gasolene 
 cars, is causing a deal of unfavorable comment. It is 
 bad enough for the perfume of the sweet-smelling brier 
 in a country lane to be polluted by an occasional passing 
 car, but in our streets and parks, with a succession of 
 passing cars, the nuisance is becoming increasingly pro- 
 nounced, and all who are interested in the future of the 
 automobile should do their best to minimize it. It is 
 mainly due to exhausting unburned fuel, and to the use 
 of either an unsuitable lubricating oil in the cylinder, 
 or one that may be very good for the purpose, but is 
 being used in excess. The splashing of oil on the muf- 
 fler, or on an air-cooled cylinder, or other hot part, will 
 also cause this trouble. Briefly, the trouble is more 
 likely to occur in engines (a) fitted with un jacketed car- 
 burettors; (&) with long and large pipes connecting the 
 carburettor to cylinder; (c) at slow speeds than at high 
 speeds; (d) in small cylinders than in large ones; (e) 
 when starting, due to condensation of the spirit vapor 
 in the cylinder, etc., and it is bound to occur whenever 
 an unclean cylinder lubricating oil of too low flash- 
 point is used. 
 
 19. Other Fuels than Gasolene. The only other fuels 
 that could be economically employed in internal com- 
 bustion engines of the motor type are benzol or benzene, 
 a spirit distilled from coal-tar, and technical or dena- 
 turized alcohol. Either of these could be used with a little 
 modification of the valves, the carburettor, and the com- 
 pression, and either would appear to be a cheaper fuel. 
 
 1 This lamp is surrounded by wire gauze, so the explosive 
 gases, though they pass free through the meshes, are so 
 cooled by contact with the comparatively cold metal and by 
 its high radiating powers, that though they may be burning 
 on one side of the gauze, the combustion ceases as the gases 
 pass through. NOTE Gasolene vapor is heavier than air.
 
 MOTOES AND MOTOEING 31 
 
 20. Air Required for Combustion. We have seen 
 that when a charge of mixture, of gasolene vapor 
 and air, is exploded in the cylinder, rapid com- 
 bustion or burning of the gas occurs, the evolution of 
 heat occurring as it burns and expands, causing the 
 piston to be pushed forward with great force. We must 
 now be clear about the elementary chemical conditions 
 which must subsist, if the chemical combination which 
 causes the explosion is to be perfect. Now, by chemical 
 analysis it is found that gasolene (hexane C 6 H 14 ), of 
 specific gravity 0.700, contains 84 per cent, of carbon 
 and 16 per cent, of hydrogen, and by the aid of chemi- 
 cal equations we can deduce the proportion of air re- 
 quired to supply oxygen enough to mix with these 
 gases, in order that when the mixture is ignited it may 
 burn so rapidly 1 as to produce a sharp explosion, no 
 gas remaining unburnt. Thus 1 Ib. of hydrogen (H) 
 requires 8 Ibs. of oxygen (0) to burn it (the product of 
 combustion being steam), and 1 Ib. of carbon (C) re- 
 quires 2 Ibs. of oxygen to burn it to carbonic acid 
 (carbonic dioxide, C0 2 ). But the composition of air 
 by weight is one of oxygen to 3 of nitrogen (N") 
 nearly, so for each pound of oxygen required 4 Ibs. of 
 air must be provided. Then to burn 1 Ib. of gasolene 
 we must have -84X2X4=10-18 Ibs. of air for the C, 
 and -16X8X4^=5-76 Ibs. of air for the H, or 10-18+ 
 5-76=15-94 Ibs. in all. But if we had taken the more 
 exact proportion of N to in the air, this would have 
 amounted to nearly 15 Ibs. to burn 1 Ib. of gasolene. 
 And as there are 13-14 cubic feet of air to the pound, at 
 a temperature of 62 F., we get 15X13-14=197, as the 
 quantity in cubic feet chemically required. Then we 
 must not forget that the hydrocarbon fuel is being 
 
 1 The rapidity depends upon the pressure reached during 
 the compression stroke. This law applies to all explosives. 
 Nobel found that a pebble of gunpowder, which took two 
 seconds for its combustion in free air, was burned in about 
 one two-hundredth part of a second under pressure in the 
 barrel of a gun.
 
 32 MOTORS AND MOTORING 
 
 burnt in the cylinder in presence of nitrogen, and some 
 of the products from the previous explosion. So it is 
 usual to allow about twice the theoretical quantity, or 
 30 Ibs., of air to completely carburate 1 Ib. of gasolene. 
 If space permitted, it would be instructive to examine 
 under what conditions of temperature, pressure, and 
 proportions a combustible gas combines completely with 
 oxygen, but as a matter of practice in running, the most 
 economical mixture to be used in the cylinder of a 
 motor is usually determined by trial at average speed, 
 the carburettor being adjusted to give the best results, 
 without the exact proportion of air and gasolene vapor 
 passing through it being known. 
 
 22. Horse-Power. In speaking of power, we must be 
 careful to distinguish it from the term force, as the two 
 words are not synonymous. The former term was very 
 loosely used by the older writers on mechanics when 
 referring to force; but power, it should be understood, 
 is the rate of doing work, that is to say, if we are to 
 measure work we must know the amount of work done 
 
 in a given time, then the quotient^ equals the power. 
 
 The unit of power was fixed by James Watt, who found, 
 by experiment, that the maximum amount of work a 
 powerful dray horse could do when pulling regularly at 
 a slow speed for eight hours a day, was at the rate of 
 33,000 foot-pounds per minute. 1 Hence one horse- 
 power=33,000 ft.-lbs. per minute. 2 So to determine 
 the horse-power (usually abbreviated to H.P.) of any 
 motor, we have simply to calculate in foot-pounds the 
 work done by it in one minute, and divide by 33,000. 
 
 But we must decide first whether we wish to measure 
 the power of the motor to do work outside itself, the 
 
 1 It is well known that the ordinary draught horse is not 
 capable of doing more than about 22,000 ft.-lbs. per minute, 
 or about two-thirds of the standard amount. 
 
 2 The French force-de-cheval, or metric horse-power=75 
 kilogram-metres per second=542.48 ft-lbs. per second, or 
 Q T 986 the horse-power,
 
 MOTOKS AND MOTOKING 33 
 
 effective power available to drive the car through the 
 gear, or do work in overcoming the friction of a clutch 
 or brake applied to its fly-wheel, which is called 'brake 
 horse-power (B.H.P.) ; J or, on the other hand, whether 
 we are to measure the indicated horse-power (I.H.P.), 
 the power developed in the cylinder of the motor by the 
 varying pressure of the expanding gases acting on the 
 piston, called indicated, because an instrument known 
 as an indicator is used to declare or indicate the varia- 
 tions in the pressure on the piston, from which the 
 mean pressure can be easily found, and this, multiplied 
 by the distance in feet per minute the piston travels in 
 doing its working strokes^ and divided by 33,000, gives 
 the indicated horse-power. 
 
 23. The Mechanical Efficiency of the Engine takes 
 account of all the frictional resistances, and compares 
 the work given out by the crank-shaft with that done in 
 the cylinder. 
 
 . . . brake horse-power 
 
 Thus, mechanical efficiency= . 7= : 
 
 indicated horse-power, 
 
 the value of the quotient varies; it decreases somewhat 
 as the size of the engine becomes very small, and also 
 decreases in any given engine as the power at which it 
 is being worked is reduced much below that which it 
 was designed to develop; this is due to the fact that its 
 frictional resistances are somewhat less at full power 
 than at any lower power, although, of course, they in- 
 crease with the power, but not quite in the same pro- 
 portion. Thus a 20 horse-power motor (if well designed 
 for that power) would probably give 17 horse-power at 
 the brakes, and would therefore have a mechanical effi- 
 ciency of 17 / 20 -85, or 85 per cent., 2 but the same en- 
 
 lr The brake horse-power is measured by using a friction 
 brake or dynamometer. It is the power some makers refer 
 to when advertising their cars. There is a marked want 
 of uniformity in accurately defining the power. 
 
 2 A good average result. When working under favorable 
 conditions, this efliciency varies from 90 to 70 per cent., that 
 is to say, from 10 to 30 per cent, of the full power developed 
 in the cylinder (the indicated horse-power) is lost.
 
 34 MOTOES AND MOTOKING 
 
 gine throttled down to 5 horse-power would probably 
 not give out more than 2 H.P. at the brake, and would 
 have a mechanical efficiency of =0-4, or 40 per cent. 
 
 This shows what has to be paid for the luxury of 
 driving a car that is powerful enough to negotiate hills 
 at a high speed, and is running at other times much 
 below its full power. 
 
 24. Fuel Efficiency of the Engine. We have re- 
 marked (Article 21) that few motors running have a 
 heat efficiency as high as 25 per cent. ; probably 20 per 
 cent, is nearer the mark the best cars reach when run- 
 ning at their highest efficiency. And, if we assume 
 their mechanical efficiency to be 75 per cent., and take 
 
 20 75 
 the product of these quantities, 
 
 we get 15 per cent, of all the energy of the fuel given 
 out in the form of work by the crank-shaft. 
 
 Now with this data before us, we will see what power 
 should be developed at the crank-shaft if we are using 
 a gallon of 0-680 gasolene per hour when running. A 
 gallon of this spirit will weigh 6-8 Ibs., 1 and we have 
 seen (Article 21) that the heat units in one pound of 
 gasolene 2 =20,748, therefore the number in one gallon= 
 6-8X20,748=141,086-4 B.T.U. (equal to 141,086X778 
 ft.-lbs.), and therefore the brake horse-power 
 
 15(141,086X778) 
 
 100(60X33,000) 
 the horse-power a motor that is burning a gallon of 
 
 1 The weight of a gallon of liquid is found by multiplying 
 its specific gravity by the weight of u gallon of water (or 
 10 Ibs.), so 0.080X10=06.8 Ibs., which is the weight of a 
 gallon of 0.680 gasolene at 59 F. 
 
 2 In article 21 we referred to gasolene of specific gravity 
 0.700, but so long as the ratio of H to C remains constant, 
 the theoretical thermal value per lb. is the same for all 
 densities. 
 
 8 This is the power given out at the crank-shaft. There 
 are further losses in transmitting it to the road wheels, as 
 we shall see.
 
 MOTORS AND MOTORING 35 
 
 gasolene an hour can be expected to give out is an av- 
 erage of 8, nearly equivalent to =11-08, say, 
 
 11 indicated horse-power. 
 
 As some cars run 30 miles (at about 20 miles per 
 hour) on a gallon of gasolene, it follows that their 
 brake horse-power and indicated horse-power can very 
 little exceed an average of X8-315=5-543, and fXll-08 
 =7-386 respectively. 
 
 Of course engines fitted with ball bearings have a 
 higher mechanical efficiency, and give out a propor- 
 tionately higher B.H.P. 
 
 IGNITION 
 
 25. There is no part of the gasolene motor of greater 
 importance than the ignition apparatus, the slightest 
 disarrangement of which invariably causes trouble, as 
 every driver soon discovers, for he finds that most stop- 
 pages are due to something abnormal occurring to this 
 all-important part. Of course, the function of the igni- 
 tion apparatus is to ignite the charge of explosive mix- 
 ture in the cylinder on or about the completion of the 
 compression stroke, when the charge is at the maximum 
 pressure due to compression, and a working stroke is 
 about to commence. This ignition was formerly very 
 generally effected by what is called 
 
 26. Tube Ignition. A small platinum tube, closed 
 at one end, being fitted to the cylinder in the combus- 
 tion chamber, the closed end projecting outside, and 
 heated to incandescence by a blow-lamp of the Bunsen 
 burner type 1 fed from the gasolene-tank, the mixture 
 being forced into the tube and ignited each time com- 
 pression occurred. It might be supposed that with this 
 
 1 There was some difficulty in keeping the lamp alight 
 when the wind caught the car in certain directions, and 
 the flame was apt to get deflected from the ignition tube, 
 allowing it to cool down enough to cause late firing, with 
 weaker explosion, and consequent loss of power.
 
 36 MOTOES AND MOTOKING 
 
 arrangement the charge would be apt to ignite before 
 the completion of the compression stroke (indeed, this 
 pre-ignition does sometimes occur, accompanied by a 
 peculiar sound, which if once heard is easily recognized), 
 retarding the piston as it nears the end of its stroke, 
 and putting a severe strain upon all the bearings; but 
 by moving the lamp to another part of the tube, farther 
 away from the cylinder, the time of firing can be re- 
 tarded, 1 and this retardation made to vary the power 
 and speed of the engine. Thus the singular synchron- 
 ism of pressure and ignition, due to the mixture be- 
 coming rapidly more explosive as its pressure increases, 
 is capable of being adjusted. Of course, should the 
 valves be leaky, the compression suffers, and the mix- 
 ture is not forced to the part of the tube directly over 
 the flame (which would be more or less filled with the 
 burnt gases from the previous stroke), the timing or 
 moment of ignition being affected with constant reduc- 
 tion in power. Again, with this arrangement, if the 
 lamp be adjusted for a certain speed, it is not right for 
 a higher or lower one, but the arrangement has been 
 made to give very good results on comparatively slow- 
 running engines, with a limited range of speed. But 
 the principal reason why tube ignition has practically 
 died out is, the time of firing the charge was not vari- 
 able at the hands of the driver. However, notwith- 
 standing these disadvantages, a few cars are still so 
 fitted as a reserve or stand-by, in case the electric igni- 
 tion should fail, but even for this purpose it is doubtful 
 if it will much longer survive, owing to the danger of 
 using a naked light on the car. To the use of an elec- 
 tric spark to ignite the explosive mixture in gasolene 
 engines at a moment which can be controlled by the 
 driver, giving him command over a wide range of 
 speed, not a little of the wonderful development of the 
 motor is due, and we must now give some attention to 
 
 1 Another arrangement used to advance and retard the 
 ignition is a nipple whose orifice can be regulated.
 
 MOTORS AND MOTORING 37 
 
 27. Electric Ignition, which is a great advance over 
 the method just described, as, with it, greater compres- 
 sion is possible and there is absolute immunity against 
 fire. Needless to say, the object of the electric ignition 
 apparatus is to produce automatically a very hot electric 
 spark (as blue as possible) in the midst of the explosive 
 mixture, at or about the moment the working stroke 
 commences. There are two systems at present in use 
 (a) the well-known high-tension ignition, involving the 
 use of induction coils, with either accumulators or bat- 
 teries, and (&) electro-magnetic ignition. 
 
 In the former the electric current is produced by 
 what we may call chemical means, whilst in the latter 
 system small dynamos or magnetos, driven by the motor 
 itself, mechanically generate the current used for firing 
 the mixture, but as they only work when the motor is 
 running, the electric current required to start the en- 
 gine has to be generated either by giving a certain speed 
 to the engine, by working the starting handle, or the 
 current for starting is supplied by an accumulator, 
 which, when necessary, is recharged by the dynamo. 
 On the other hand, these machines have many advan- 
 tages, not the least important of which is freedom from 
 stoppages due to short circuits and leakage; they also 
 can be made to give a hotter spark than primary bat- 
 teries and accumulators and are therefore more capable 
 of causing complete ignition of a big charge, but, as at 
 present made, their delicate construction makes them 
 liable to give a deal of trouble. However, there are 
 several types striving for supremacy, 1 and it is not 
 possible to predict the ultimate issue; so, many makers 
 and motorists are awaiting developments before making 
 any change in their ignition arrangements. 
 
 Although the balance is in favor of the final form 
 being of the electro-magnetic type, the high-tension igni- 
 tion system, with accumulators and induction coils, pre- 
 
 1 There is sure to be some marked improvements and 
 interesting developments in this direction before long.
 
 38 MOTORS AXD MOTORING 
 
 viously referred to, still holds its own, owing to its sim- 
 plicity and reliability, and, therefore, may be briefly 
 examined, but the exigencies of space forbid the author 
 doing anything like justice to it. Referring to Fig. 1, 
 it will be seen that this electrical system consists of (1) 
 the accumulator or battery, (2) the coil, (3) the com- 
 mutator or contact maker and breaker, (4) the spark- 
 ing plug, (5) the switch; and we may now proceed to 
 describe these parts before attempting to explain how 
 they must be linked up to form a complete system; so 
 we may commence with 
 
 28. The Battery, or Accumulator. This is called a 
 primary battery if it is so arranged that electricity is 
 created by the chemical action of acid solution upon 
 zinc and carbon plates, but if it consists of a series of 
 lead grids or plates, some filled with a paste of peroxide 
 of lead, forming the positive element, and others filled 
 with pure lead in a finely divided or spongy condition 
 forming the negative element, placed in a liquid-proof 
 receptacle filled with water acidulated with sulphuric 
 acid, it is an accumulator (or secondary or storage bat- 
 tery), which can accumulate or store 1 within itself a 
 charge of electricity from a dynamo, or a primary bat- 
 tery of suitable construction. When discharged, both 
 
 1 Strictly speaking, it does not actually store electricity. 
 The lead plates and lead-peroxide, by means of a continuous 
 current or charge from some outside source, are so changed 
 that they become capable, owing to their chemical condi- 
 tion, of themselves creating a flow of electricity when the 
 circuit is closed. The usual cells are of two distinct types 
 namely, the Plante, in which the active material is chem- 
 ically or electrically formed out of the surface of the leaden 
 conductor, and the Faure, in which the active material is 
 formed into a paste, and is caused to adhere to a lead grid 
 or conductor. The former type is superior for durability, 
 but the latter has the great advantage of being much less 
 expensive in manufacture. Most of the accumulators now 
 made are one or the other of these types, only differing in 
 constructional details. They all have a very low internal 
 resistance compared with any form of primary battery. 
 Some automobile makers now use accumulators fitted with 
 Plante positive plates and Faure negatives for traction.
 
 MOTORS AND MOTORING 39 
 
 the positive, or lead-peroxide plates, and the negative, 
 or spongy lead plates, are largely converted into lead 
 sulphate. When being charged, the lead sulphate un- 
 dergoes a chemical change, due to the electrolytic action 
 of the charging current, which converts the positive 
 plates once more into peroxide of lead, and the negative 
 plates into spongy metallic lead. These two elements 
 in the sulphuric acid solution give an electro-motive 
 force of about 2-2 volts. Thus the accumulator creates 
 electrical energy in the same sense as a primary battery 
 does, i.e., by chemical action, but is renewable, when 
 exhausted, by passing through it a current of electricity 
 from another source, in the opposite direction to that 
 taken from it in discharging. 1 
 
 Accumulators are more generally used than primary 
 batteries, for although they have not the same capacity 
 (will not be efficient for so many miles) bulk for bulk, 
 when properly used they have not to be replaced by new 
 ones after they have become exhausted, as must be 
 done with the latter. 2 As in both cases the method of 
 using them and their function is the same, either can 
 be used in this system of ignition, but for the reasons 
 given we will assume that accumulators are preferred. 
 Now, each accumulator is fitted with two terminals, 
 called positive and negative poles, arranged so that 
 
 1 The life of the accumulator greatly depends upon the 
 care taken in charging and discharging, and upon the purity 
 of the materials used, and it is false economy to buy anything 
 but the best cells. 
 
 2 Primary batteries are usually dry ones, modifications 
 of the simple voltaic elements, zinc and carbon, of constant 
 or non-polarlzable type, filled with some material to prevent 
 the liquid electrolyte from spilling. A battery usually con- 
 sists of four cells, and although the initial cost of these is 
 far less than that of accumulators, and they are capable of 
 standing rougher and more irregular treatment, they are 
 not so economical, as their energy depends upon the con- 
 sumption of the zinc plates, and when these have been used 
 up, the cells are practically worthless, and must be replaced. 
 So, for continual use, this makes them ultimately twice as 
 costly as accumulators.
 
 40 MOTORS AND MOTORING 
 
 wires can be connected to them by means of set screws. 
 If these terminals be connected by a wire (completing 
 the circuit), electricity will flow from the positive to 
 the negative terminal continuously, and in so doing 
 will gradually discharge the accumulator. Electricity 
 flows with very little resistance through all metallic 
 substances, and with more resistance through water or 
 across any moist or wet surface. If a wire carrying a 
 current comes into contact with any metallic substance 
 in more than one place, the current will divide between 
 the two; in this case the wire is said to be short-cir- 
 cuited at that part. Therefore, in conveying current 
 from one part of the motor to another x the wires must 
 be (insulated) covered with insulating materials, those 
 of an india-rubber nature being found most efficient. 
 The higher the tension or pressure used to urge the 
 current through the circuit, the thicker must the non- 
 conducting cover be, for if the insulation be not suffi- 
 ciently good, electricity may leak through the engine 
 frame to the negative pole (become short-circuited, or 
 shorted, as it is sometimes called). Now, the electrical 
 current, as it is discharged from the accumulator, is not 
 lacking in quantity (amperage), 2 but it is of too low 
 voltage 3 or pressure, and to get a current to pass, in 
 the form of sparks, across the small insulating gap at 
 the end of the sparking plug, the pressure must be 
 
 *To reduce the resistance to a minimum, and avoid the 
 chance of leakage, these connections should be as direct 
 and short as possible, and great care should be taken in 
 making them. 
 
 2 The ampere is the unit of current, or the unit rate of 
 flow of electricity ; and the ampere-hour equals the ampere 
 flowing for one hour. 
 
 3 The volt is the unit of pressure, electro-motive force 
 (B.M.F.), or potential difference (P.D.). The unit of 
 resistance which the conductor offers to the flow of current 
 through it is the Ohm, and E.M.F.=AmperesXOhrns. 
 
 The watt equals the ampere multiplied by the volt, and 
 the watt-hour equals the energy expended in one hour by 
 one watt, which equals 3600 joules, or 3600 X. 7373=2654.28 
 foot-pounds.
 
 MOTORS AND MOTORING 41 
 
 raised from that of the accumulator cells, viz., about 
 4-4 volts, to some thousands of volts; so, to transform 
 it into the high-tension current necessary for this pur- 
 pose, it is passed through an 
 
 29. Induction Coil. When the current flows from 
 the accumulator, it is conducted through several turns 
 of insulated wire (about 20 gauge), wound round a 
 central core of soft iron wire. This is known as the 
 "primary" or "low-tension" winding. From there 
 it passes to a contact-breaker, which automatically 
 opens and closes the circuit, and then flows back to the 
 accumulator, so completing the circuit. Round this 
 primary coil (but well insulated from it) is wound a 
 second coil of very many turns of fine wire (about 32 
 gauge), the ends of which are connected to the termi- 
 nals of the sparking plug. This coil is known as the 
 " secondary " or " high-tension " winding. When the 
 primary current flows, it magnetizes the iron core and 
 the magnetic field established interlinks with the very 
 many turns of the secondary coil; it also immediately 
 attracts the iron armature of the contact-breaker, and 
 so breaks the circuit. The magnetic field then disap- 
 pears, and the spring of the contact-breaker pulls the 
 armature back to its original position. This again com- 
 pletes the circuit, and the magnetic field once more 
 interlinks with the secondary coil, and the whole opera- 
 tion is repeated in this way several times a second. 
 
 The magnetic field, in surging through the secondary 
 coil of many turns, induces in it an electrical pressure 
 high enough to break down the insulating gap at the 
 sparking plug points, resulting in a discharge across it 
 in the form of sparks, which ignites the explosive mix- 
 ture in the cylinder. The power and efficiency of the 
 coil is greatly increased by being fitted with a condenser, 
 made up of a series of alternate layers of fine tinfoil 
 and paraffined-waxed paper, the connections being so 
 made that when the current through the primary wind- 
 ing is interrupted by the vibration of the trembler, the 
 condenser acts as a " shunt circuit," and stores up en-
 
 42 MOTORS AND MOTORING 
 
 ergy which would otherwise dissipate itself in a very 
 destructive spark at the platinum contacts of the cir- 
 cuit-breaker/ and this stored-up energy helps the cur- 
 rent to rise quickly in the primary coils at the next 
 making of the circuit. The efficiency of the spark de- 
 pends on the large number of turns in the secondary 
 winding as compared with the primary turns, also on 
 the rapidity with which the primary circuit is broken, 
 and on the strong magnetic field of the soft iron core 
 when temporarily turned into a powerful magnet. 
 Another important detail of the system is the 
 
 30. Contact-Breaker, or Commutator. 2 This is gen- 
 erally of the wiping contact type 3 as shown in Fig. 1, 
 and consists of an insulated disc (usually made of fiber) 
 fixed to the half-speed shaft. At a fixed point on this 
 disc is a sector of brass connected directly to the shaft, 
 which again is in metallic contact with the frame of the 
 motor. 
 
 A metal brush or collector, insulated from the frame 
 of the engine, and in metallic contact with one terminal 
 of the primary coil, ordinarily rests on the insulated 
 disc, and we shall explain directly what part this com- 
 mutator plays in the complete system. 
 
 31. The Sparking Plug. The principal features of 
 the sparking plug or igniter are shown in Fig. 11, which 
 
 1 If an inefficient condenser be fitted a strong spark is 
 obtained when the circuit between the platinum-pointed 
 screw and trembler is broken, which quickly causes unsat- 
 isfactory working by burning away the contacts, necessi- 
 tating readjustments and wasting current. 
 
 2 The two terms contact-breaker and commutator are not 
 synonymous, therefore they must be correctly used. A con- 
 tact-breaker is fitted to a single-cylinder engine, and a com- 
 mutator to a multi-cylinder one, though in both cases, 
 types and designs may be precisely similar. In the latter 
 case its function is to commute the current from one path 
 to another, or, more explicitly, from one cylinder to another. 
 In the well-known apparatus introduced by Mr. F. C. Blake 
 of Kew, two or more cylinders are fired by means of a 
 single coil with a high-speed trembler. 
 
 "The other type, which was formerly so much used, is 
 the spring-blade or trembler contact-breaker.
 
 MOTORS AND MOTORING 43 
 
 represents the De Dion Bouton new pattern plug. Into 
 a brass or gun-metal shell S (which is screwed into a 
 cylinder wall, and is in metallic contact with it) a hol- 
 low non-conducting plug D, made of porcelain (or com- 
 pressed mica), is held in position by the gland nut N, 
 and through plug D a wire is fixed, the pointed end P 
 being of platinum, and the other end E being in me- 
 tallic contact with the brass cap C, on to which the 
 insulated copper wire from the induction coil, carrying 
 the high-tension current, is screwed by the brass fly- 
 nut P, placing the platinum point P in metallic con- 
 tact with the wire from the coil. The other platinum 
 point Q is fixed in the brass shell S, so that PQ forms 
 
 SPARKING PLUG. 
 WATER SPACE 
 
 BRASS 
 
 Fig. 11. 
 
 the spark gap, and we shall explain directly what occurs 
 when the plug is in use. 
 
 32. External Plug Gap. By introducing a second 
 gap into the high-tension circuit, a spark can be main- 
 tained inside the cylinder under conditions which 
 would otherwise prevent any effective ignition taking 
 place, and contrivances have been introduced for at- 
 taching to the sparking plug, so that external sparks
 
 44 MOTORS AND MOTORING 
 
 can be obtained. This not only intensifies the spark, 
 but assists in preventing trouble due to sooting of the 
 plug, and enables the driver to see at a glance whether 
 current is passing through each of the plugs; and 
 another advantage is, he has not to resort to the com- 
 mon but clumsy method of discovering an erring plug 
 by opening the coil box and holding down the trembler, 
 so that one cylinder is left in at a time. These plugs 
 appear to be dropping out of favor. 
 
 33. The Switch is a simple contrivance by means of 
 which the primary circuit can easily be made or broken 
 by a small movement of the metal connecting piece. 
 The switch is used for momentary breaks in running 
 the engine ; by its use the current from the accumulator 
 is switched on or off the induction coil. Of course the 
 switch is used to break or make the circuit when the 
 engine is stopped or started. There are several types of 
 switch, the latest and most convenient for motor cycles 
 being that operated by the preliminary movement of 
 applying the brake. 
 
 34. An Interrupter is merely a means of conveniently 
 breaking the circuit when the motor is not to be used 
 for a considerable period. Motor bicycles are generally 
 fitted with a plug interrupter, which can be carried in 
 the cyclist's pocket when the machine is not being used. 
 
 35. The Complete Ignition System. We may now 
 summarize the various parts which, connected together, 
 form the complete system. Commencing with the accu- 
 mulator, Fig. 1, we have one of its poles connected with 
 one end of the primary coil of the induction coil, the 
 other end being connected (through the switch) to the 
 brush of the contact-breaker, so that the low-tension 
 current can pass through the disc to the engine frame 
 and from the frame to the accumulator again, through 
 the connecting wire (called earth wire). When the 
 switch is on and the motor revolving, the half-speed 
 shaft turns until the metal segment N touches the brush 
 or collector ; this completes the circuit, and the cur- 
 rent passes through the primary coil, agitates the trem-
 
 MOTORS AND MOTORING 45 
 
 bier, and the high-tension current is induced to the sec- 
 ondary coil. This high-tension or secondary current 
 passes directly to the insulated portion of the sparking 
 plug (as shown, Fig. 11), and being, as it were, im- 
 prisoned on all sides by insulated material through 
 which it cannot escape, jumps across the space between 
 the platinum points, in the path of least resistance, and 
 in so doing produces at the right moment a stream of 
 intensely hot sparks in the gap between the sparking 
 plug points, igniting the explosive mixture surround- 
 ing it. The high-tension circuit being completed 
 through the engine frame and earth wire to induction 
 coil. 
 
 36. Accumulators, Charging, etc. The accumulator 
 used for our purpose l usually consists of two cells, each 
 with a voltage of 2-2, and being connected in series, 2 
 as they always are for this ignition apparatus, the 
 result is a working voltage of 2X2-2 = 4-4, but when 
 the cells are fully charged, it may almost reach 5 volts. 
 There are several methods of charging accumulators, 
 but we need only mention the following three. First 
 Charging from primary batteries. This is a method 
 that is within the reach of every motorist who is not 
 afraid of a little trouble. The first cost of a good four- 
 cell primary battery does not amount to much, and the 
 same remark applies to the cost of charging, if all the 
 materials are used up before they are replaced. If 
 the motorist has only a very limited knowledge of 
 electricity, he would be wise to get an electrician to 
 arrange everything for him at first and this advice also 
 applies to the other two methods to be explained ; indeed, 
 many car-owners prefer to send their accumulators to 
 the makers, or to an agent who undertakes the work, 
 to be recharged, rather than be bothered or run any 
 
 Accumulators are used for lighting, as well as for igni- 
 tion and traction. 
 
 2 In series, the positive or peroxide pole of one cell (usu- 
 ally painted red) is connected to the negative or spongy 
 lead plate of the next cell.
 
 46 MOTOKS AND MOTOKING 
 
 risk of making mistakes; but they should make an 
 effort to understand these things to protect themselves, 
 and to be able to put things right in case of emergency. 
 The second method is by charging from electric mains, 
 using lamps solely as a resistance: this is by far the 
 most popular, but unless several cells can be charged 
 at the same time, it is the most extravagant. The third 
 method, which is by far the best when practicable, is 
 to charge from electric mains, using, as a resistance, 
 lamps which would in any case be used for lighting 
 purposes. It entails a small outlay for slightly altering 
 the wiring of the room to be used, but should the car- 
 owner have the electric light in his coach-house, it can 
 be easily arranged for the purpose, and the accumula- 
 tors can then be charged when the lights are used for 
 ordinary purposes, the only noticeable effect of this 
 being a slight decrease in the intensity of the light; 
 the current then practically costs nothing. An addi- 
 tional advantage due to this way of charging is that 
 accumulators can be kept nearly always fully charged. 
 Indeed, they should be charged whenever possible, to 
 keep them in order. Of course, it must be direct cur- 
 rent electricity, as an alternating current would charge 
 and discharge with each alternation. Now, to keep the 
 cells in order, it is best not to withdraw more than 
 about 25 per cent, of the total charge from them before 
 recharging; but much more, say up to 70 or 75 per 
 cent., can be discharged if the cells are recharged 
 immediately. They should always be fully charged 
 before being put out of action for any considerable time, 
 as there is a constant tendency for an automatic dis- 
 charge to occur. The normal discharge rate through 
 a coil of good construction is about half an ampere, 
 so that if the accumulator cells have a capacity, as 
 many of them have, of 40 ampere-hours/ and the read- 
 
 lr The quantity of electricity flowing into or out of an 
 accumulator is computed in ampere-hours, and the rate at 
 which it passes a given point in the circuit is indicated in 
 amperes.
 
 MOTOBS AND MOTOEING 47 
 
 ing of the ammeter * is half an ampere, and about 50 
 per cent, of the total charge be withdrawn, it can be 
 used for about 40 hours; but suppose the commutator 
 only makes contact for one-fourth of a revolution, the 
 accumulator is only giving current for one-fourth of the 
 time, then it can be run for 4 X 40, or 160 working 
 hours. 
 
 All accumulators are constructed to charge and dis- 
 charge at a certain rate, and any attempt to force the 
 rate of either charging or discharging inevitably results 
 in the peroxide paste being forced out of the grids, 
 and the latter being bent and buckled by the stress. 
 This often occurs due to shorting, when the terminals 
 are connected by a good conductor to ascertain what 
 charge, if any, remains in the accumulator. Of course 
 this should never be done without a resistance, such 
 as the coil, in circuit, nor should the ampere-meter be 
 connected direct across the terminals, as in either case 
 it would allow the accumulator to discharge at many 
 times its correct rate. On the other hand, a volt-meter 2 
 may be connected in this way to take the reading, as 
 it has a high resistance, and takes but an infinitesimal 
 current. 
 
 This brings us to the question of measuring the 
 charge in the accumulator. 
 
 37. The Voltage of the Current. Let us assume that 
 we have before us an accumulator consisting of the 
 usual two cells fully charged, each to a voltage of 2-2, 
 giving a voltage of 4-4 when connected in series and 
 tested with the volt-meter. We may also assume that 
 on being tested with an ammeter 3 (connected up to 
 
 1 The ammeter, or ampere-meter, is an instrument for 
 indicating the rate of charge or discharge in amperes. 
 
 2 An instrument for indicating the electro-motive-force, or 
 the electrical pressure in a circuit, or at the terminals of a 
 battery or dynamo. 
 
 8 In testing dry batteries for capacity, an ammeter should 
 be used, not a voltmeter, because the voltage indicated when 
 the battery is nearly run out is almost the same as when 
 new; the resistance of the battery and voltmeter together
 
 48 MOTORS AND MOTORING 
 
 the coil whilst working and included in series connec- 
 tion 1 ) its discharge rate is found to be half an ampere, 
 and that the charge is 30 ampere-hours, 2 we should 
 find that as the current is discharged there is a gradual 
 fall in the voltage, until, when about half has been 
 withdrawn, the voltage would be only about 4, and if 
 the withdrawal of current be continued, the fall in 
 voltage becomes far more rapid till it drops to 3-6, 
 at which reading the accumulator is considered to be 
 exhausted or discharged. 
 
 38. Spare Accumulators. It is usual to carry a spare 
 set of accumulators, and these are often connected up 
 by a two-way switch, so that they can be put in circuit 
 and the others disconnected at any moment. This 
 arrangement takes up no more room than the four-cell 
 primary battery it often replaces. 
 
 39. testing on a Closed Circuit. The expedient of 
 using a small incandescent lamp of the same voltage as 
 the accumulator is a good one. This is connected across 
 the terminals for a moment or two, and if it lights up 
 brightly and the light is sustained, then there is a 
 charge in the accumulator, but if it becomes dim, then 
 
 to the passage of a current being relatively high, whether 
 the battery be nearly exhausted or almost new. On the 
 other hand, an ammeter offers small resistance, and, if used 
 just long enough to obtain a reading, will indicate by the 
 quantity of current passing through it the condition of the 
 battery; for as the battery becomes exhausted its resist- 
 ance increases, and its capacity for giving out current 
 becomes reduced. 
 
 iThe internal resistance of the accumulator being very 
 low, unless a resistance, such as a coil, be placed in the 
 circuit, both the ammeter and the accumulator would be 
 damaged, the latter being quickly run down, and the wind- 
 ing of the former seriously over-heated. 
 
 2 The amount of electric energy given out by an accumu- 
 lator is always less than the amount put in ; and the former, 
 compared with the latter, represents the efficiency, which 
 varies from 70 to 80 per cent., according to the age of the 
 accumulator and the rate of charging, being highest when 
 new and slowly charged.
 
 MOTOES AND MOTORING 49 
 
 the accumulator is exhausted. This test should always 
 be made at the conclusion of a run, as the accumulator 
 is capable of recovering sufficiently while standing to 
 give a fairly bright light for a few moments, even 
 when almost exhausted. As this is a test of current 
 and voltage, it is very reliable, for a reading with a 
 volt-meter (testing an open circuit} will sometimes be 
 almost normal, and a fall of voltage occur as soon as 
 current is withdrawn. 
 
 GOVERNING AND CONTROLLING 
 
 40. One of the most difficult problems the designer 
 of a gasolene engine has to deal with is the governing of 
 its power and speed. He is called upon to arrange its 
 mechanism in such a way that the engine automatically 
 prevents the production of more power in itself than 
 is actually needed for the propulsion of the car at any 
 particular speed. To give practical effect to this con- 
 dition, designers have exercised their ingenuity in a 
 variety of ways, but they have a more difficult task to 
 deal with in the gasolene engine than in either the steam 
 engine or ordinary gas engine, as we shall see directly. 
 It is easy to make arrangements to enable the driver to 
 control' 1 the engine; and as these arrangements have 
 much in common with those employed in governing, 
 we may proceed to explain that the amount of useful 
 work done by a gasolene engine during a cycle can be 
 varied in several ways, the following being the best 
 known. 
 
 (1) Advancing and retarding the ignition, the 
 
 charge being constant. 
 
 (2) Advancing and retarding ignition with fluctu- 
 
 ating charge. 
 
 (3) Varying the amount of charge by throttling, the 
 
 proportion of the mixture being constant. 
 
 1 The function of governing differs from that of control- 
 ling ; the engine is governed automatically, but controlled 
 by hand,
 
 50 MOTOES AND MOTOKING 
 
 (4) By throttling the exhaust. 
 
 In order to grasp the general principles that underlie 
 the working of the first and second methods, the reader 
 must make himself familiar with the effect of 
 
 41. Advancing and Retarding Ignition. The power 
 of the engine can he varied between fairly wide limits 
 by varying the time of ignition. If ignition is to occur 
 at the beginning of a working stroke for running the 
 engine at its full power, the brush of the commutator 
 (Figs. 1 and 16) should commence to come into con- 
 tact with the metallic connecting plate on the insulated 
 disc slightly before the piston has completed its com- 
 pression stroke; as although, theoretically, sparking 
 should occur at the instant the circuit is completed, an 
 appreciable interval intervenes between ignition and 
 the completion of the circuit. This is partly due to the 
 number of points through which the current passes, 
 some of which may not be very perfect, and to the fact 
 that there is always an interval of time between spark- 
 ing and actual ignition, the time required to ignite the 
 mixture depending upon the proportion of air to spirit 
 vapor forming it, upon the amount of compression, and 
 also upon the proportion of the exhaust gases mingling 
 with the explosive mixture. The interval being shortest 
 when the mixture is perfect and at maximum com- 
 pression, and increasing as the mixture becomes 
 throttled with a smaller quantity entering the cylinder, 
 which in mixing with the normal quantity of exhaust 
 gases in the clearance or combustion space, results in 
 an impoverished mixture at a lower compression, 1 and 
 a later ignition. This being the case, the expedient of 
 causing sparking to occur a little earlier, that is, by 
 
 lr rhe more the mixture is throttled, the smaller is the 
 volume which is compressed in the cylinder, and the lower 
 the pressure due to compression. Thus, if the cylinder is 
 fully charged at atmospheric pressure, the charge be com- 
 pressed to one-fourth the initial volume, then at greatest 
 compression, neglecting refinements, the resulting pressure 
 would be 4 times atmospheric pressure, or, say 4X15=60;
 
 MOTOES AND MOTOKING 51 
 
 advancing the spark, is one that would suggest itself; 
 indeed, it is the one that is generally employed, although 
 in most cases in a somewhat casual way. The object 
 should be to so time the ignition that the greatest 
 pressure due to it occurs at the commencement of the 
 working stroke at all speeds. Therefore the usual 
 practice is to advance the spark as the speed of the 
 engine increases, and, conversely, to retard it as the 
 speed is reduced. Great care must be taken to avoid 
 pre-ignition * with its attendant damaging effects. If 
 the sparking is so timed that ignition occurs after the 
 piston has started on its working stroke, the ignition 
 is said to be retarded, and the effect of this is to reduce 
 the amount of work done in the cylinder during this 
 stroke. Engineers are able to examine the variation 
 of pressure in the cylinder, during the complete cycle, 
 by using an instrument called an indicator. When 
 using the ordinary form of this instrument, a pencil 
 point traces out a curved figure on a sheet of paper or 
 card, 2 as it is called, and from it the pressure on the 
 piston at all points in its stroke can be measured, a 
 mean of these pressures giving the mean pressure 3 
 throughout the stroke. The area of the figure formed 
 by the expansion and compression lines (3 and 2, Fig. 
 12 4 ) is a measure of the work done during the stroke, 
 whilst the area of the figure bounded by the exhaust 
 and suction lines 4 and 1 (same Fig.), represents the 
 
 but if, on the other hand, due to throttling the cylinder is 
 charged with only half a full volume when the compression 
 begins (this means doing negative work during suction 
 stroke), then, obviously, the compression cannot exceed 
 2X15=30 pounds per square inch. 
 
 1 Refer to Article 43. 
 
 2 The ordinary instrument does not give satisfactory re- 
 sults at very high speeds, but the beautiful Hospitalier- 
 Carpentier Manograph indicates efficiently at 2000 to 3000 
 revolutions. 
 
 3 This is the pressure which is used in measuring the 
 indicated horse-power of the engine. 
 
 4 The Figs, are slightly contorted, so that all the lines 
 may be clearly seen.
 
 53 MOTOES AND MOTORING 
 
 negative work done by the engine when acting as a 
 pump during the suction stroke. The indicator dia- 
 gram not only shows the behavior of the working fluid 
 in the cylinder, but it reveals any defect in the valve 
 setting, timing of ignition, and general action. 
 
 42. Late Ignition. The diagram (Fig. 13) shows 
 what occurs when the spark is retarded to reduce the 
 power of the engine. It will be seen that the piston has 
 traveled to nearly half stroke before the highest pres- 
 sure (which is much less than in the normal case) is 
 reached, the smaller area of the part 2, 3, showing the 
 reduced amount of work done, although the same 
 amount of mixture may have been drawn into the 
 cylinder as for Fig. 12; but the rate of propagation of 
 the flame throughout the charge is slow compared with 
 the piston velocity, due to the lower compression, and 
 the gases are only partially burned when allowed to 
 escape by the exhaust, their temperature and pressure 
 being much higher than in the normal case; indeed, 
 the temperature is often so high that the long-con- 
 tinued action of the hot gases on the exhaust valves 
 ultimately destroys them. Moreover, this is obviously 
 a very uneconomical way of working, as about the 
 same quantity of fuel is used per stroke for different 
 powers, so all this shows the evil of governing by spark 
 variation. 
 
 43. Pre-Ignition. Fig. 14 shows how, when the mix- 
 ture is sparked too early (pre-ignited), the explosion 
 suddenly sends the pressure up to a high point, before 
 the completion of the compression stroke, tending to 
 stop the engine, and severely straining it. This action 
 also leads to a certain amount of negative work being 
 done in the cylinder during the cycle, as it will be seen 
 that more work is done by the piston on the gases 
 during compression, than is done on the piston during 
 the expansion stroke. This negative work is represented 
 by the area 2, 3. 
 
 44. Back-Firing, or explosion during the suction 
 stroke or early part of compression stroke (Fig. 15),
 
 MOTORS AND MOTOEING 
 
 53 
 
 ATMOS
 
 54 MOTOKS AND MOTOKITO 
 
 sometimes occurs. It is caused by overheated valves or 
 smoldering exhaust gases, and its effect upon the 
 piston, etc., is similar to that just explained in con- 
 nection with pre-ignition. 
 
 It will now be convenient to consider how the timing 
 of the spark is actually effected, and an examination 
 of Fig. 16 will help us in this matter, it represents a 
 
 45. Commutator or Current Distributor of the Pan- 
 hard type. T (Fig. 16) is the end view of the half- 
 speed shaft, and M that of the disc, made of a non- 
 conducting material, usually of a fibrous character; it 
 is keyed to shaft T, and is fitted with a metal plate K, 
 which is put in metallic contact with the shaft T, which 
 is in the electric circuit, by means of a screw or pin N. 
 The shell or body G has a boss at the back which is 
 bored to fit the shaft, so that its arm or lever C can 
 move it and its fittings freely in either of the directions 
 shown by the arrows; into the projecting bosses HH 
 insulating sleeves or brush holders FF are screwed, and 
 into these again the brass tubes VV are screwed. These 
 tubes contain the brushes BB, which are made of coiled 
 wire gauze, held in contact with the edges of the disc 
 by the helical springs SS, which press against the brass 
 split caps DD; bolts or screws 00 clipping the cap on 
 the tube, the wires EE placing the brushes BB in 
 metallic contact with the coils. Obviously, this com- 
 mutator is arranged to serve two cylinders with cranks 
 side-by-side, as in the Mors engine, the number of 
 bosses HH and their fittings corresponding with the 
 number of the engine's cylinders (with cranks at 180, 
 the bosses would of course be at 90 to one another). 
 The link J is connected to the working handle by 
 suitable rods, wire cables, and levers. A movement of 
 C to the left, as can be seen, will cause ignition to occur 
 later, or the spark will be retarded, just as a movement 
 in the opposite direction will bring the brushes nearer 
 the advancing metallic contact piece, and hasten igni- 
 tion or advance the spark.
 
 MOTOES AND MOTOEING 
 
 55 
 
 46. Governing and Controlling by Throttling the 
 Mixture, sometimes called charge volume throttling (or 
 governing on the inlet), is the system which is by far 
 the most popular. A governor of the crank-shaft cen- 
 trifugal type is fitted, usually on the half-speed shaft, 
 
 COMMUTATOR OE CUEEENT DISTEIBUTOE 
 
 (Panhard Type) FOE CEANKS SIDE BY SIDE 
 
 I 
 
 and arranged, in the majority of cars now in use, to 
 actuate a throttle valve placed in the induction pipe 
 of the cylinders, 1 this valve is either of the butterfly a 
 
 lr The quantity is regulated in the Duryea and Bollee 
 cars by giving the inlet valve a variable lift. 
 *The tendency of many engines fitted with this valve is
 
 56 MOTORS AND MOTORING 
 
 (as shown in Fig. 6 at T) or cylindrical type. It is 
 regulated so that when the car is running on level 
 ground with a smooth surface, the engine is working 
 in an economical manner; the governor only allowing 
 sufficient explosive mixture to enter the cylinder to 
 produce the amount of work that the resistance due to 
 the condition of the road, direction, and velocity of the 
 wind call for. Should this resistance increase, through 
 any of the causes mentioned, or owing to the car coming 
 to rising ground, the engine slows down and the gov- 
 ernor automatically opens the throttle to enable a larger 
 charge to pass into the cylinder, and, conversely, the 
 governor commences to close the valve as soon as the 
 engine begins to race above its normal speed. Some 
 engines are so fitted that the throttle can also be con- 
 trolled by hand or foot. 
 
 47. Accelerator. To enable the engine to exert its 
 maximum power for hill-climbing, an arrangement 
 called an accelerator is fitted; it is merely a combina- 
 tion of levers, wire cable, and spring, fixed up to con- 
 nect the governor to either a lever fitted to the steering 
 column, or to a pedal projecting through the foot-board 
 (the latter being the more usual arrangement), so that 
 by a movement of the lever or pedal, the weights of the 
 governor are prevented from exerting their power to 
 close the throttle; in other words, it cuts out the gov- 
 ernor's action, the throttle remaining open, allowing 
 the speed of the engine to increase above its normal 
 rate, and the engine to work at its maximum power, 
 which is obviously what is required if a steep grade is 
 
 to run in jerks, first gaining speed, then slowing down too 
 much under the action of the governor, or, in other words, 
 the governor hunts; but this un-uniform action has been 
 largely checked, and the running much improved, by drilling 
 a hole about \ inch in diameter through the disc of the 
 valve, to form a by-pass. Probably in some cases the uni- 
 formity of running would be much improved by the gov- 
 ernor being fitted with a dash-pot arrangement, but at the 
 best, with light loads, throttle governing is more or less 
 unstable.
 
 MOTORS AND MOTORING 57 
 
 to be mounted without changing gear; but should the 
 car then fail to make headway, the gear is changed 
 to a lower one, 1 and the accelerator is thrown out of 
 action, allowing the governor to act again, and the 
 engine to run at its normal speed. The accelerator 
 should never be used unless really required if the 
 engine is to be economically worked. 
 
 48. Governing on the Exhaust. In this system a hit 
 and miss arrangement, actuated by a centrifugal gov- 
 ernor of the crank-shaft type, permits the exhaust valve 
 to be raised in the ordinary way when the engine is 
 working within its maximum speed limit, but when the 
 latter is reached a digger is withdrawn from the exhaust 
 valve spindle or plunger by the action of the governor, 
 so that the valve remains unlifted, and the burnt charge 
 is retained within the cylinder; or the opening of this 
 valve is retarded, a portion of the burnt gases remaining 
 in the cylinder to dilute the next charge admitted. 
 This so reduces the speed of the engine, that the next 
 exhaust stroke is a normal one, and the ordinary cycle 
 of operations is taken up again. With this system there 
 is, of course, a loss due to back pressure, but the cylinder 
 being kept full, the compression does not suffer, and the 
 mixture is therefore more economically consumed, 
 although, when the engine runs light, there is a loss of 
 economy, as the incoming cold charge mingles with the 
 hot burnt gases, making a high temperature mixture 
 before compression. Not a little of the economy of the 
 Gillet-Foust, and other motors, is claimed for this sys- 
 tem of governing, and it is thought much of by some 
 whose opinions are entitled to respect, although it has 
 practically died out, and is only now seen on old cars 
 which are still running. 
 
 1 Drivers easily get into a way of manipulating the clutch 
 to enable them to mount the crest of rising ground without 
 changing gear. As the engine slows down, the clutch is 
 momentarily withdrawn to allow the engine to gain speed, 
 and is let in again before the car has had time to be much 
 reduced in speed. For obvious reasons this expedient must 
 be worked with moderation.
 
 58 MOTORS AND MOTORING 
 
 CYLINDER COOLING 
 
 49. When it is remembered that somewhere in the 
 cylinder during each working stroke there may be a 
 temperature of some 3600 F., tapering off to about 
 1800 to 2000 F. as the burnt gases pass out of the 
 cylinder, and that the temperature of the cylinder-wall 
 must be low enough to allow of the piston being effi- 
 ciently lubricated, the importance of providing suitable 
 arrangements for keeping the cylinder sufficiently cool 
 can be realized. To make the conditions under which 
 the piston can satisfactorily work in the cylinder a little 
 more clear, it should be explained that the maximum 
 temperature referred to is more or less evolved at the 
 kernel of the mixture, the temperature near the 
 cylinder-wall probably being not much more than half 
 that amount, and that of the wall itself about 250 F. 
 Further, these high temperatures are much reduced 
 during the suction stroke, when the cool mixture enters, 
 also during the compression stroke, although not to the 
 same extent, 1 so that the heat imparted to the cylinder 
 each cycle is not so much as might at first be expected ; 
 nevertheless, as an engine making 1000 revolutions a 
 minute will perform a cycle in V 500 of a minute, or 
 rather less than | of a second, the rapid succession of 
 heat increments could soon raise the temperature of the 
 cylinder to a point when effective lubrication would be 
 impossible, so to keep the temperature of the cylinder 
 down to a safe point, special arrangements have to be 
 made. So far as very small engines (such as are used 
 on low-power motor bicycles) are concerned, it is suffi- 
 cient to increase the outer surface of the cylinder, by 
 an arrangement of either radiating or circular flanges 
 or ribs, 2 so that in passing through the air it may be 
 cooled as much as possible. The cooling efficiency of 
 
 *A great deal of heat is generated in compressing the 
 mixture. 
 
 2 Circular flanges are best, as the air can more completely 
 sweep round them, and they materially add to the strength 
 of the cylinder.
 
 MOTOES AND MOTOEING 59 
 
 this arrangement (or of the air-cooled tubes of a 
 radiator) depends upon the velocity of the encountering 
 air, the extent of the surface in contact with that air, 
 and the difference in temperature between the inner 
 surface and the air in contact with the exterior surface. 
 It is found that when this simple method is intelligently 
 carried out, the cylinders of engines up to about 3 horse- 
 power can be effectively cooled, but with larger powers 
 the problem becomes one that requires the assistance 
 of an additional cooling agency to solve it; hence the 
 evolution of the arrangement diagrammatically shown 
 in Fig. 1, where it will be seen that the cylinder has a 
 jacket surrounding it, through which water is circu- 
 lated l by a centrifugal pump 2 (P.O.) which forces 
 the water to circulate through the cooling system, 
 entering the jacket at the lowest part a, and leaving it 
 at the top Jj, passing through the connecting pipe 3 into 
 the radiator to the tank 4 at a level of about its center c, 
 and leaving it at its bottom d to enter the pump again. 
 
 1 There is another system in use, in which cooling is 
 effected by water evaporation within the jacket 
 
 2 This pump is found, on the whole, to be the most satis- 
 factory for the purpose. If made a decent size, not requir- 
 ing to be run at a high speed, and gear driven, as many now 
 are, it works well, and is not affected by dirt in the water. 
 Other types, such as the rotary-force and the simple gear, 
 have been tried and used by a few makers, but although 
 they give an excellent circulation when perfect, they soon 
 wear out, and their first cost is greater, to say nothing of 
 the difficulty of keeping their wearing parts lubricated with- 
 out introducing into the cylinder jacket and tubes an oily 
 viscous coating that much impairs their efficiency. 
 
 3 These pipes are often made too small, and with bends 
 much too sharp, to allow of a free and unrestricted circula- 
 tion. They should not be less than f inch diameter, and the 
 bends should have a radius of at least some five diameters 
 when practicable. 
 
 4 The connections c and d to the tank should be as far 
 away from one another as possible ; so as to get a good cir- 
 culation of water in the tank, they are usually placed at 
 opposite ends, as shown. The tank is fitted with a filling 
 hole, usually covered with a screwed bung, and an open 
 tube from the highest part, bent over the tank side to allow 
 any steam that may be generated to escape.
 
 60 MOTOES AND MOTOKING 
 
 If the tank and radiator be sufficiently large, and fixed 
 high enough above the engine, 1 a very fair natural cir- 
 culation results without using a pump; in fact, this 
 gravity or thermo-syphon system has the great advan- 
 tage of simplicity to recommend it, and formerly was 
 much used, and still is used with advantage on very 
 light cars. Thus the introduction of forced circulation, 
 with the indispensable pump, which in some form or 
 another is general, has reduced the weight of the cool- 
 ing system, and increased its efficiency, but has added 
 to the number of parts which require attention and are 
 liable to give trouble. The cooling system being a 
 vital part of the motor, it greatly reduces the possibility 
 of annoying stoppages when fitted so that in case of 
 emergency the pump can be thrown out of circuit, and 
 the engine run on low speed and power with natural 
 or gravity circulation. 
 
 50. Radiators. There are two types of radiators in 
 use, namely, the multitubular and coil. The former 
 was first brought out on the famous Mercedes car. In 
 this the water is made to circulate around a great num- 
 ber (in some cases amounting to 5000 or 6000) of small 
 tubes fixed about 1 / 16 of an inch apart, its principal 
 advantage being the small volume and weight of water 
 used, some few pints only being required. Its draw- 
 backs are that the workmanship must be of the very 
 highest class, or leakage troubles will occur. Eadiators 
 of this type are very difficult to repair, and the pas- 
 sages being so very small, they are liable to get choked. 
 In the other or ordinary type, the well-known ribbed 
 or gilled pipe coil, the section of the pipe is usually 
 circular, 2 and the surface of the gills flat, although 
 
 1 Vibration, and the slight yielding of the frame when the 
 car is roughly used, cause the connections to become leaky ; 
 so, for this reason, armored rubber hose is to be preferred 
 for the connections, which should always be long enough to 
 prevent undue straining actions. 
 
 2 A flattened tube has a larger cooling surface than a cir- 
 cular one of the same sectional area, but it offers more 
 resistance to the flow through it, particularly at the bends.
 
 MOTOES AND MOTOBDTG 61 
 
 some of the latter are corrugated, the idea being that 
 as they expose more surface to the action of the air, 
 they are more efficient, but it has been proved that this 
 is not the case, the corrugations retarding the passage 
 of air between them, and causing as much loss of cooling 
 effect as was gained by the extra surface. With either 
 type a float-glass, in which the position of the float 
 indicates the condition of the circulation, is fixed to the 
 dash-board, or the water passes through a glass tube 
 fixed there, so that the condition of the circulation can 
 be seen at a glance. 
 
 51. Air Fans are now generally used, but unless these 
 be skillfully designed, and run at a speed sufficiently 
 high (which, by the way, requires a fair amount of 
 power), they can easily be worse than useless. 1 Indeed, 
 in not a few cases that the writer has come across, the 
 efficiency of the motor would have been increased by 
 scrapping the fan and paying a little more attention to 
 the condition of the surface of the radiator, which 
 should be so treated that heat leaves it with the greatest 
 freedom. Now, strangely enough, all bright and 
 polished surfaces reluctantly part with their heat, 2 
 whilst most dull rough ones freely lose it, therefore the 
 common practice of blackleading and polishing cylin- 
 ders and cooling pipes, or coating them with metallic 
 paints, impairs the efficiency of the rough surface. 
 The best stuff known for coating purposes is lampblack, 
 and the rougher the surface to which this is applied, 
 the more easily will it part with its heat. 
 
 52. Air-Locking. Trouble sometimes occurs due to 
 the system becoming air-locked in filling up with water, 
 an air-bubble forming in the top of a bend and getting 
 compressed and set instead of circulating when the 
 pump begins to work. This of course means that the 
 flow of water is stopped, with consequent boiling away 
 
 1 They also draw the dust from the roads, and the hot air 
 off the radiators on to the engine, which is a drawback. 
 
 2 Part of the heat is carried or conducted away by the air 
 in contact with the surfaces, and part by radiation.
 
 62 MOTOKS AND MOTOEING 
 
 of that portion of the water which is kept in contact 
 with the cylinder, it not being free to pass through the 
 radiator, which quickly becomes hotter at the upper 
 part than at the bottom; so, if a sensible difference of 
 temperature be detected in these parts after the engine 
 has been running a few minutes, it means that there is 
 either an air-lock or the pump is not working; if the 
 former, it may sometimes be relieved by opening the 
 air-cock, which is generally fitted to the top of the 
 radiator, or, this failing to give relief, by drawing off 
 the water and continuing to fill up the tank while the 
 engine is running slowly. 
 
 MUFFLERS 
 
 53. No one can fail to have noticed what a marked 
 improvement has been made during the past year or 
 two in muffling, or deadening, the sound of the exhaust 
 gases from gasolene motors, and all must agree that this 
 
 TYPICAL MUFFLER 
 
 Fig. v. 
 
 .is a step in the right direction, indeed, one well worth 
 making if we have not to pay too dearly for it in greatly 
 reduced effective power, which is the price represented 
 by want of skill in designing the silencer. The problem 
 to be solved is, how to deaden the noise caused by the 
 sudden liberation of the exhaust gases under pressure. 
 The engine,, as used at the present time> emits the
 
 MOTOKS AND MOTOKING 63 
 
 products of combustion at such a pressure that they 
 expand violently, striking the surrounding air, and 
 causing the sensation which we know as a noise or 
 explosion. Now, the silencing method usually adopted 
 is to muffle this noise by passing the gases into a 
 cylinder of considerable capacity, to allow them to 
 expand with little resistance till their pressure is equal 
 to that of the atmosphere; their path through the 
 cylinder being made more or less tortuous by baffles and 
 perforated pipes, with the object of breaking up the 
 sound-waves and reducing their velocity, so that the 
 gases pass out of the silencer nearly inert and noiseless. 
 
 Another principle has been applied lately with a fair 
 amount of success; the gases are discharged through a 
 large number of little holes in a muffler of very small 
 dimensions, the idea being to break up the large 
 explosion into very many small ones, which, not syn- 
 chronizing, more or less cancel one another. But any 
 attempt to reduce the dimensions of the muffler below 
 a certain capacity, which depends upon size of the cylin- 
 der and pressure of the gases as they leave the exhaust 
 valve, must mean an increase of back pressure. Some 
 cars are fitted with a by-pass valve, so that the driver 
 can temporarily allow the gases to escape without all 
 passing through the muffler, thereby reducing the back 
 pressure, and giving the motor a little extra power when 
 required. 
 
 A very good idea of how a typical muffler works can 
 be formed by examining Fig. 17, where, if the arrows 
 be followed, it will be seen that the gases pass through 
 in a zig-zag way, increasing in volume, and, therefore, 
 decreasing in pressure, as they near the outlet to the 
 atmosphere at the end B. 
 
 54. Back-Firing or Popping in the muffler is nearly 
 always caused through the mixture being too weak; the 
 charge is not then exploded in the cylinder, but passes 
 out of the exhaust valve into the muffler, where it is 
 ignited by the heat of the exhaust pipe or passages. 
 When the speed of a motor is suddenly checked, the
 
 64 MOTOES AND MOTOKING 
 
 piston does not move quick enough to suck in a suffi- 
 cient quantity of spray to carburate the air, so the 
 remedy is to push the mixture lever forward when sud- 
 denly reducing speed. 
 
 TRANSMISSION GEAR 
 
 55. If a side view of the engine in Fig. 1 had been 
 shown, it would have been seen that the crank-shaft is 
 fitted with a fly-wheel, whose function in a reciproca- 
 ting engine is well understood, as most people are aware 
 that not a little of the even running of a gasolene en- 
 gine, with its one working stroke in four, is due to this 
 important part being of sufficient size and weight. Of 
 course it is keyed to the tail of the crank-shaft, as shown 
 in Fig. 18 at D, and in most cases it is made with a 
 conical hole arranged to form, with the male conical 
 block C, a friction clutch. This clutch is used to con- 
 nect the road wheels with the motor through a mechan- 
 ism called the transmission gear. And two forms of 
 this gear now hold the field, one, called chain gear, in 
 which side chains are used to drive the back road wheels, 
 which are loose on the axle, and the other in which the 
 power is transmitted to the back axle, by tooth gearing, 
 causing it to rotate and carry with it the rear road 
 wheel's, which are in this case fixed to it. To understand 
 these arrangements, and to be clear about what hap- 
 pens when a car is reversed, or put on a different speed 
 by a change of gear, the reader is referred to Figs. 18 
 and 19, which diagrammatically show typical examples 
 of these gears. The former illustrates the system of 
 Driving through Side-Chains, and it will be seen that 
 the male part C of the clutch is kept in frictional con- 
 tact with the fly-wheel part D, by the action of the com- 
 pressed helical spring S, the friction between them due 
 to the spring being great enough to enable the engine 
 to drive the car through the clutch. A bell-crank 
 lever, with a fork at one end and a pedal at the other, is
 
 MOTOES AND MOTORING 65 
 
 fitted to the grooved collar M, as shown in Fig. 20, in 
 such a way that when the pedal G is pushed, the spring 
 is compressed and the clutch thrown out of action. 
 Now, although this small end movement of the clutch 
 cone C in relation to the shaft N can take place, they 
 are so coupled 1 that when C is " let in," and is rotating 
 about the axis, the shaft N is made to turn with it. 
 Keyed to N (Fig. 18) are three wheels, E, B, and P (E 
 and B are used for running ahead, 2 and P for revers- 
 ing), each of which is arranged to mesh with one of 
 the wheels on the sleeve GO. Now this sleeve is usually 
 made with a square hole fitting the shaft RV, which 
 is square to fit it. 3 The sleeve has on it a grooved col- 
 lar, which engages a sliding fork F, suitably connected 
 at L, to the change-speed lever fixed at the right hand 
 side of the car, and this lever works in a quadrant with 
 four notches, one of these corresponding to the position 
 of the sleeve shown with the second speed * wheels in 
 mesh. 
 
 Another position (due to a movement of L towards 
 the right, and the lever into another notch) places the 
 first speed wheels G and E in mesh, whilst a movement 
 of L to the left throws all the wheels out of mesh, and 
 the engine is free to rotate without driving the shaft 
 VR. This of course is the position of the sleeve when 
 the car is standing still and the engine is running, the 
 change-speed lever being in the neutral notch. The 
 fourth notch fixes the position of the lever for reversing 
 the car. When this notch is used, the sleeve is moved 
 
 lr The clutch C driving the shaft N through a feather 
 fitted to the latter. 
 
 2 It will be noticed that, for simplicity's sake, the gear-box 
 in this example only contains two pairs of forward wheels 
 and a reverse, corresponding to two speeds of the car for 
 a given speed of the engine. Of course, a motor arranged 
 in this way would be more dependent upon the elasticity 
 of the engine (or power of varying its speed) than one 
 fitted with three or four speeds. 
 
 8 Or the shaft is round, and fitted with a feather arranged 
 to drive the sleeve. 
 
 4 In this case the highest speed.
 
 MOTORS AND MOTORING 67 
 
 to the left till the wheels and P are opposite. then 
 comes into mesh with another wheel, called a change 
 wheel, running on a third shaft above it (not shown 
 in the Fig.) which connects the two wheels, but causes 
 the wheel and the shaft VE to rotate in same direc- 
 tion, thus reversing the car. 
 
 It should hardly be necessary to explain that the shaft 
 VE drives the differential shaft DS, through the bevel 
 wheels J and H and the box D containing the differen- 
 tial gear 1 ; the shaft DS, in its turn, driving the road 
 wheels through the chains as shown, and in the way that 
 everyone who owns a common bicycle understands. 
 
 The other kind of transmission gear referred to is 
 the 
 
 56. Live-Axle or Cardan Drive, in which the power 
 of the engine is transmitted to the road wheels by tooth- 
 gear throughout. This system, which is becoming in- 
 creasingly popular, can be understood by an examina- 
 tion of the explanatory diagram Fig. 19. It will be 
 noticed, that from the motor to the gearing box GB, 
 the mechanism is the same as in Fig. 18; indeed, the 
 greater part of the gear and box is identical with that 
 previously described in connection with that figure, but 
 in Fig. 19 the tail of the shaft GE is connected to the 
 bevel pinion c by the propeller or Cardan shaft ps, two 
 flexible or universal joints 2 a and b being fitted to the 
 shaft to allow full play of the carriage-spring system 
 between the road-wheel axle and the frame which sup- 
 ports the motor and gear-box. 
 
 Now the bevel pinion c is in mesh with the bevel 
 wheel d, which forms part of the differential gear-box 
 T, through which motion is transmitted to the axle of 
 the driving wheels. 
 
 ^ne form of this Interesting and indispensable gear is 
 shown in section on the live-axle in Fig. 19, and its action 
 is referred to in the next article. 
 
 2 These joints are perhaps best known as Hooke's, the 
 inventor being Dr. Hooke, the famous scientist. They are 
 also sometimes called Cardan joints.
 
 MOTORS AND MOTORING 69 
 
 It will now be convenient to give a little attention to 
 some of the details that have been referred to in con- 
 nection with the two systems of transmission, so we 
 may commence with 
 
 57. The Differential Gear, which is a train of wheels 
 elegantly arranged to average the speeds of the two 
 driving wheels, for, when the car turns a corner or runs 
 round a bend in the road, the outer road wheel will be 
 traveling faster than the inner one; but the propeller 
 shaft can only revolve at one speed at any given mo- 
 ment, and that, therefore, must be the average of the 
 two speeds, due to the running of the inner and outer 
 road wheel. Although it is not easy, without suitable 
 drawings, to make clear to the general reader how this 
 arrangement works, the following experiment will help 
 him, at any rate, to understand the function of this 
 important fitting. Jack up the road-driving wheels to 
 clear the ground, place the change-speed lever in the 
 neutral notch, then turn by hand one of the road 
 wheels n (Fig. 19), and the other wheel ra will revolve 
 in the opposite direction at the same speed, the average 
 speed being zero. Again, let one of the wheels, say n, 
 be fixed, and the bevel wheel d be turned, it will be 
 found that the other road wheel m will revolve at twice 
 the speed of d 1 or the speed of d is the average of the 
 speeds of m and n, as before. And so, if in turning a 
 corner n revolved at 70 a minute and m at 80, d would 
 be running at the mean or average 75. 
 
 One of the most important details of a transmission 
 gear is 
 
 58. The Clutch, as at any moment, when a car is run- 
 ning, the safety of the vehicle, indeed, the safety of the 
 
 1 The box T revolving with the bevel wheel d carries with 
 it the two (or more) bevel pinions (called epicyclic, owing 
 to their movement around the axis of motion) e and f, 
 which, being in mesh with the stationary pinion h, cause 
 the pinion g, and the axle i to which it is fixed (h being 
 also fixed to axle ;), to revolve at twice the speed of d, the 
 pinion g being carried round once by e and / and driven 
 once by being in mesh with h.
 
 70 MOTORS AND MOTORING 
 
 occupants, may be jeopardized by its faulty action, for, 
 when in working order, a push on the pedal instantly 
 disconnects the motor from the transmission gear, and 
 the car can be stopped by an application of the brakes; 
 but should the clutch seize at a critical moment, this 
 release cannot be made without a deal of trouble, and 
 it is easy to imagine what might happen. Fortunately, 
 this is a mishap which rarely occurs, indeed, should 
 never occur, if the clutch is made with a suitable taper, 
 and care is taken in a metal to metal contact to keep the 
 surfaces lubricated. In this connection it should be ex- 
 plained that the surfaces of the male cone is generally 
 faced with leather, 1 to increase the amount of friction, 
 copper being occasionally used instead. 2 
 
 59. Fierce Clutches. Clutches may cause trouble, 
 either by slipping too much 3 or by not slipping enough ; 
 in the latter case they are said to be fierce, and the cause 
 
 1 The leather is usually riveted to the conical surface of the 
 male part of the clutch by copper rivets. These are first 
 screwed into the cone and hammered down, till the heads 
 are rather more than inch below the surface of the 
 leather, the holes in the latter having been previously 
 countersunk. When the riveting is completed, a light cut 
 is taken off the leather in a lathe, so that its surface is truly 
 conical and the right taper. The leather ultimately wears 
 down to the rivets, and when this occurs, the clutch is apt 
 to become very fierce, owing to the rivet heads seizing the 
 metal of the clutch ; they then require hammering down 
 till they are well below the surface again. 
 
 2 There appears to be a growing tendency to dispense with 
 a facing, and run the clutch with bare iron contact. 
 
 3 Slip may be due to too much oil getting on to the leather 
 face ; this may be remedied by applying a little Fuller's 
 earth, chalk, or lime. But slip may also be due to the 
 spring being too weak ; if this be the cause, the spring must 
 be further compressed by screwing up the adjusting nut. 
 The clutch should be so adjusted that it is just on the point 
 of slipping when the car is exerting its full power in mount- 
 ing a hill on its lowest speed. Often this means a good deal 
 of strain on the ankle for a long run, and the temptation to 
 ease the spring is great, but it should be remembered that 
 slip means loss of power.
 
 MOTORS AND MOTOEINQ 71 
 
 is either the presence of gritty dirt on the leather, 1 or 
 the spring being too strong. If due to dirt, the leather 
 should be washed with gasolene, and dressed with a small 
 quantity of castor or Collan oil; this makes and keeps 
 the leather soft and pliable, and allows the necessary 
 slip to take place should the clutch be accidentally 
 allowed to too suddenly engage. If this treatment does 
 not improve matters, and the clutch takes up its work 
 too rapidly, causing the car to plunge forward, subject- 
 ing the whole vehicle to abnormal strains, instead of 
 gradually moving off, as it should do, then the com- 
 pression of the spring must be relieved by unscrewing 
 the adjusting nut to increase its length. A little pa- 
 tient attention to these matters will enable the driver, 
 by a give and take correction, to put the clutch in proper 
 working order. Of course, with a conical clutch as 
 ordinarily arranged, there is a certain amount of thrust 
 in both directions, due to the spring, which requires at- 
 tention, this being sometimes taken on ball bearings; 
 and it is owing to this that expanding clutches, which 
 cause little or no thrust, are coming into use, but the 
 difficulty has been ingeniously overcome in 
 
 60. The Panhard Clutch, which is diagrammatically 
 shown in Fig. 20. It will be seen that in this arrange- 
 ment the dished fly-wheel F is bolted on to the tail of 
 the crank-shaft CS, which is flanged at A for that pur- 
 pose. Through the rim of the fly-wheel, pins PP are 
 fastened, the projecting parts passing through holes in 
 the flange of the male cone C to enable the fly-wheel to 
 drive the latter. The female cone B is attached to the 
 hollow clutch shaft N, 2 so that when the clutch is en- 
 gaged, the helical spring S presses the grooved collar 
 M against the cone C, forcing it into cone B, and in so 
 
 1 Fierceness is also caused by renewing the leather fac- 
 ing ; the remedy is, apply the clutch gently until the leather 
 wears down and becomes fairly smooth. 
 
 2 This shaft is usually coupled to the change-gear shaft 
 N (Fig. 18) by a sleeve, inside of which is a distance price, 
 so that by opening the coupling sleeve and removing the 
 distance price, the clutch and shaft can be removed.
 
 72 MOTORS AND MOTORING 
 
 doing creating friction enough to enable the car to be 
 driven through the clutch. The reaction at the other 
 end of the spring is exerted by the adjustable collar-nut 
 D, so that the opposite forces are completely balanced, 
 without any thrust being thrown on the crank-shaft or 
 gear-box. This balance, it should be explained, is dis- 
 
 PANHARD CLUTCH. 
 
 turbed when the pedal G is pushed to disengage the 
 clutch, an additional pressure is then exerted on the 
 collar D, thrusting the shaft N to the right, but a 
 thrust block E is arranged to receive that. There is 
 also a thrust bearing at to transmit the thrust of 
 the spring to the cone C. It will be noticed that the
 
 MOTORS AND MOTORIKO 73 
 
 cone end of the shaft fits into the boss R of the fly- 
 wheel, thereby keeping the shafts in perfect alignment, 
 which is a most important condition to satisfy. In 
 some cars, such as the Canstatt Daimler, and the Mer- 
 cedes Simplex, the withdrawal of the clutch automati- 
 cally reduces the speed of the engine, whilst in most 
 cases the act of applying the foot-brake disengages the 
 clutch. 
 
 61. Gear Changing. In the case of cars fitted with 
 the ordinary or Panhard gear, one of the most delicate 
 operations the driver has frequently to perform is gear 
 changing, for if this is not done with sufficient skill and 
 . care, the teeth of the wheels are apt to be seriously dam- 
 aged and the car abnormally strained. We have seen 
 that in changing from one gear to another, the teeth of 
 the wheels which are in mesh have to be disengaged and 
 those of others put into mesh by a sliding movement; 
 now, obviously, for this to be done sweetly, the spaces 
 must be just opposite the teeth they are to engage, but 
 should they not thus coincide, much grinding, if not a 
 broken tooth, may result in a clumsy attempt to engage 
 them. 1 
 
 Certain precautions should be taken in gear chang- 
 ing; for example, let us suppose that a car is in motion 
 on fairly level ground, with, say, the second speed gear 
 in, and it is decided to change up to the third speed, 
 the clutch pedal should be pressed down to disengage 
 the clutch and allow the car and gear to continue run- 
 ning by its momentum, then with a pull on the speed- 
 lever the second speed wheels are disengaged, and an 
 
 1 This gear is without question the weak link in the 
 ordinary car ; that it is a barbarous device, although a con- 
 venient one, no one doubts, and its ultimate disuse as at 
 present arranged can be sagely predicted ; although they 
 have been much improved by beveling the tooth-faces and 
 increasing the pitch, it is not so easy to indicate upon what 
 lines further improvement will be made. There are already 
 in use gears that can be easily and safely changed, the 
 teeth being always in mesh, the tightening of a band-brake 
 bringing a particular gear into use.
 
 74 MOTOES AND MOTORING 
 
 attempt made to put into mesh the teeth of the third 
 speed wheels; this must not be done until the delicate 
 sense of touch has conveyed a message that spaces and 
 teeth coincide, when a sharp pull or jerk will engage the 
 wheels. Now, in running on the level or on a down 
 grade, this operation need not be performed hurriedly, 
 indeed, it is best done gently ; but in putting in a lower 
 gear up-hill, not a moment is to be lost, otherwise the 
 car rapidly slows, and if time is lost in the change, the 
 load on the engine suddenly becomes greater when the 
 wheels get into mesh, often requiring a little relief by 
 slightly disengaging the clutch, allowing a little slip- 
 ping to keep the engine running above the speed at 
 which it is apt to stop. There is always the danger, 
 when changing speed in mounting a hill, of missing the 
 gear altogether, the car then quickly commencing to 
 run back. In fact, not a few most serious accidents 
 have happened in this way. This being so, we will care- 
 fully indicate what should be done in negotiating a hill 
 which requires a change of gear. Now, as soon as the 
 car gets on rising ground, the accelerator pedal should 
 be pressed to allow the engine to exert its full power 
 on the gear it is running with (which will probably be 
 its highest one), then, immediately before withdrawing 
 the clutch, the accelerator pedal is released, 1 and on the 
 clutch being disengaged the speed-lever is promptly 
 moved over to the required notch, 2 corresponding to the 
 second or first speed, as the case may be, and when this 
 has been done the clutch should be gently put in, allow- 
 ing slip to occur, until the engine takes up the full 
 
 lr This enables the governor to check the racing of the 
 engine during the moment or two required for changing the 
 gear. 
 
 2 A deal of practice is required to do this with certainty 
 in the dark or without looking. The expedient of connect- 
 ing a little electric light-up with the gear-lever and the 
 ordinary four-volt cells used for ignition, in such a manner 
 that when changing gear the light automatically comes into 
 action, and immediately goes out again on reaching the 
 proper notch or gear, was introduced some year or two ago, 
 but there are obvious objections to its use.
 
 MOTORS AND MOTORING 75 
 
 load, when the clutch pedal is released and the acceler- 
 ator put in action. Briefly, a gear should be put in at 
 the moment the two wheels that are to be placed in 
 mesh are running at the same circumferential speed. 
 
 62. Chain Driving. Although during the past year 
 or two there have been an increasing number of makers 
 who have adopted the system of live-axle and gear 
 transmission, particularly for light cars, there are still 
 a great many who pin their faith to chain driving, with 
 its rather greater simplicity and flexibility, the fact of 
 the matter being that either system is in a way a com- 
 promise, each one having its advantages and disadvan- 
 tages. The former system, perhaps, on the whole, is 
 considered by engineers the best mechanical- arrange- 
 ment; certainly the working parts are better protected, 
 but the divided axle is a drawback, and should it acci- 
 dentally get bent, it means a big job to get it right 
 again, or even true enough to get home with, whilst a 
 village blacksmith can straighten the axle of a chain- 
 driven car with certainty. On the other hand, chains 
 are apt to break, and should one give way and the other 
 continue driving, the car may be overturned if going at 
 a high speed; of course, most cars carry a spare chain, 
 or at least spare links that can be fitted on the road 
 should it be necessary. After chains have been in use 
 some time they stretch and become loose, and have to 
 be taken up either by lengthening the stretcher bar 1 or 
 taking out a link. Chains as ordinarily used are rarely 
 run at their highest efficiency, 2 as it is quite the excep- 
 tion to see any attempt made to properly lubricate them 
 and keep the dirt off. Users of the common bicycle 
 
 1 The stretcher bar, or distance rod, is used as an adjust- 
 able connection between the axle and the differential shaft, 
 the distance between which would vary considerably with 
 the deflection of the springs were this rod not used. 
 
 2 When the teeth of the sprocket wheels are correctly 
 formed, it is mostly rolling friction which occurs, and this 
 accounts for the liberties that can be taken with chains in 
 lubricating them. But the want of alignment, that is so 
 often noticed, even in the best cars, means loss of efficiency.
 
 ?6 MOTORS AtfD MOTORING 
 
 understand the advantage of using a gear-case with the 
 chain running in oil; it is true that there are difficul- 
 ties in fitting cars this way, but it is not easy to under- 
 stand why some protection has not heen more generally 
 given to car chains; so, as things are, periodical atten- 
 tion must be given to 
 
 63. Cleaning and Lubricating the Chains. They 
 should be first thoroughly cleaned with paraffin, then 
 soaked in melted refined 1 Eussian tallow, care being 
 taken not to allow the tallow to become hotter than is 
 necessary to keep it in the liquid state, as the temper of 
 the chain may be affected. After the chain has been 
 moved about in the melted grease to allow it, the grease, 
 to come in contact with the surfaces of the rollers and 
 rivets, the chain should be hung up and the lubricant 
 allowed to drain into the shallow tin used for the pur- 
 pose. Plumbago and tallow make an excellent lubri- 
 cant, but it is very difficult to effectually apply, as the 
 plumbago sinks to the bottom of the vessel as soon as 
 the tallow becomes melted. 
 
 64. Brakes. Every car must by law be fitted with at 
 least two brakes, but most cars of any importance have 
 three, one at each driving wheel, and one somewhere on 
 the primary shaft, and it is almost the universal prac- 
 tice to make one of these (generally the latter) a foot- 
 brake, arranged to withdraw the clutch as the brake is 
 applied, and in some cases to also throttle the mixture. 
 The second brake (or brakes) is usually worked by a 
 side-hand lever; this brake should on no account be 
 made to disengage the clutch when it is used, as the 
 engine itself can be made to act in cases of emergency 
 as an auxiliary brake, 2 if the clutch remains engaged. 
 
 ^he tallow can be refined by placing it in a pail of boil- 
 ing water, stirring till it is all melted, when the foreign 
 matter will be precipitated, and a solid block of clean tallow 
 form on the surface when cooled. 
 
 2 A car sometimes stops on a hill, which for some reason 
 or other it can't climb ; the tendency then is for the weight 
 of the car to gradually make the engine run backwards and 
 allow the vehicle to descend the hill ; of course, as soon as
 
 MOTORS AND MOTORING 77 
 
 Most cars are fitted with band brakes on the driving 
 wheels, as shown in Fig. 18, but several makers have 
 abandoned these in favor of some form of expanding 
 brake acting on the inner surface of a ring or annular 
 flange. 1 It is imperatively necessary that all car brakes 
 should be so constructed that they are equally effective 
 whether the car be moving forward or backward, for 
 upon the perfect working of the brakes depends the 
 safety of the car and its occupants. 
 
 The conditions which a good brake should satisfy 
 are the following: 
 
 (1) The maximum force required to work it by foot 
 or hand to be one that can be applied without undue 
 exertion. 
 
 this happens the sprag should be lowered, and if this holds 
 before the car gets on too much way all is well, but it is 
 easy to see that so long as the clutch is in, the friction and 
 compression in the cylinder retard the motion of the car, 
 and the withdrawal of the clutch cuts out this resistance, 
 often with a resulting increase in the velocity of the car 
 before the hand or emergency brake can be put on, although 
 the foot-brake be at once applied. This must not be con- 
 fused with what is done when a car is running forward, and 
 its speed is suddenly arrested by an application of the 
 brake; the foot-brake is then used, the clutch being with- 
 drawn by the same pedal, instantly disconnects the clutch 
 shaft from the engine, which then runs unloaded. This 
 arrangement gives the driver wonderful control over the 
 car, as its stoppage is not dependent upon his power to 
 suddenly bring up his engine to a standstill. Of course the 
 beauty of the system is that when the car is temporarily 
 stopped the engine continues running, so that a restart can 
 be instantly made by letting in the clutch. Indeed, it is 
 not easy for those who have not driven a car to understand 
 what perfect control the driver has over it; for instance, 
 it was proved by brake tests carried out by the Automobile 
 Club of America that over 70 feet were required to pull up 
 a four-in-hand coach running at about sixteen miles per 
 hour, whilst a Panhard car running at the same speed was 
 brought to a standstill in 25 ft. 4 ins. 
 
 *In chain drives this is a particular form of sprocket 
 ring. With such arrangements it is practicable to better 
 protect the rubbing surfaces from oil and dirt, which reduce 
 their efficiency, and increase the wear and tear, but they are 
 less get-at-able and more difficult to examine.
 
 78 MOTOKS AND MOTORING 
 
 (2) The movement of pedal or lever to apply the full 
 power of the brake not to be more than can be conven- 
 iently made by the driver. 
 
 (3) The bands or blocks to be suspended in such a 
 way that they are only in contact with the brake, pulley, 
 ring, or flange when the brake is applied, 1 being at 
 least a inch clear all round at other times. 
 
 (4) Absence of fierceness in the action of the brake. 2 
 No part of the car requires more intelligent care in 
 
 its manipulation than the brake, if it is to be worked 
 when necessary for all it is worth without abnormal 
 injury to the tires. It works with the greatest effect 
 when the tires, due to its application, are just on the 
 point of skidding ; 3 for when skidding occurs the rub- 
 ber is eroded, and the friction between ground and tire 
 is very much decreased instead of becoming greater, as 
 most people would expect. 
 
 65. Ball Bearings. Headers who are old enough to 
 have ridden a bicycle before the introduction of ball 
 bearings, and have had riding experience with both 
 kinds, will be in a position to estimate the marked ad- 
 vantage ball bearings have over ordinary ones, so far 
 as frictional resistance is concerned, and with cars this 
 difference is just as striking ; indeed, a few things appear 
 to be more perfect than the running of car wheels, 
 mounted on well-adjusted ball bearings; but the ball 
 bearing has an advantage over the plain bearing, only 
 so long as the hard steel balls remain in perfect form, 
 
 *A common source of trouble in the way of noise, wear, 
 and loss of power, is the rubbing of brake-bands, due to 
 want of adjustment or faulty construction. 
 
 2 The true function of a brake is to retard a wheel, not 
 lock it; should it do the latter, then the tires must skid, 
 and the most expensive part of the car (the tires) is seri- 
 ously worn and injured, instead of a little wear occurring in 
 the strap and ring, which can be easily replaced. 
 
 3 The old-fashioned spoon-type brake, acting directly upon 
 the tread of the tire, was abandoned on account of its low 
 efficiency and the manner in which it used to wear out the 
 cover of the tire.
 
 MOTOES AND MOTOKING 79 
 
 and no longer, for should a ball break, there is always 
 the probability that a portion or portions of the ball 
 may get across or become jammed in the ball races, 
 scoring them or the axle, or both, whilst in some cases 
 the axles have been held tight and fractured by the sud- 
 den strain. Frequently ball bearings are allowed to 
 run far too long without attention and lubrication, with 
 the result that when they are inspected some of the 
 balls are found to have worn sharp or rough, and per- 
 haps to have grooved the cups and cones of the races 
 upon which they run. Eenewing the latter is, of course, 
 an expensive matter; it is much more economical to 
 replace the whole of the balls as soon as there is any 
 appreciable sign of wear, even if a single ball is faulty, 
 as a new one would have to be exactly the same size as 
 the others, and few people are capable of gauging the 
 size with sufficient accuracy. Obviously, if one of the 
 balls happens to be a shade larger than the others, it 
 will, each time it reaches the bottom of its race, support 
 the whole weight, and sooner or later will break. To 
 be on the safe side, these bearings should be examined 
 every 1000 miles, and the balls renewed about every 
 5000 miles. In placing balls in their races, care must 
 be taken not to get them too crowded; indeed, if there 
 is any doubt as to whether a certain number can be 
 got in, it is better to put in one less, and be sure that 
 they are not jammed together when the cone is screwed 
 up. 
 
 If no lubricator is provided for the hub barrel, the 
 axle cap should be taken off, filled with grease, and 
 screwed right home, every few hundred miles; this will 
 force the grease into both races, and keep things right. 
 Ball bearings require careful adjustment to keep them 
 in order, the adjusting cone being tightened till all 
 side shake has been taken up, and the wheel is solid on 
 its bearing ; at the same time, it must run with the most 
 absolute freedom. Of course this adjustment can only 
 be made when the wheel is jacked up clear of the 
 ground; and it should be remembered that the adjust-
 
 80 MOTOES AND MOTOKING 
 
 ing nuts, upon the right-hand side wheels, are made 
 with a right-hand thread, whilst those on the left-hand 
 side of the car are fitted with a left-hand threaded ad- 
 justing nut. The reason of this arrangement should 
 he obvious, for should the lock-nut by any means work 
 loose, the tendency of the adjusting nuts on both sides, 
 due to the motion of the wheels in contact with them, 
 is to tighten themselves upon the axle. 
 
 66. The Tires. We may now give some attention to 
 the vexed question of the tires. Should they be solid 
 or pneumatic? is a question, like so many others relat- 
 ing to motor vehicles, that cannot be answered definitely 
 without qualifications. The principal factors which 
 have to be considered in making a decision, being the 
 maximum speed the car is to run at, the character of 
 the roads the car is to run on (i.e., is the car required 
 for town or touring purposes?), the weight of the 
 vehicle, the size and flexibility of its springs, comfort, 
 and reliability. Those who have had long experience 
 with pneumatic tires, particularly if they have run 
 them after they have given unmistakable signs of de- 
 preciation, would willingly sacrifice a little comfort if 
 they could secure immunity from tire troubles by adopt- 
 ing solids ; but even with solid rubber tires we have not 
 perfect reliability, as, under exceptional circumstances, 
 the fixing cement is apt to get heated enough by road 
 friction to melt, and allow the tires to creep slightly on 
 the rims, the cement accumulating at some parts of the 
 latter to an extent sufficient to gradually force the tires 
 from them, causing, at the same time, an abrasive action 
 between the tires and rims, the tendency of the tires to 
 leave the rims being increased by the centrifugal force, 
 when running at a high speed. Moreover, the use of 
 solid tires necessitates the use of springs of greater 
 flexibility; and provision must be made for a greater 
 vertical movement between the frame and axles, which 
 means, in most chain-driven cars, a varying tightness 
 of the chains, and in gear-driven ones, a greater varia- 
 tion in the uniformity of transmission, due to the
 
 MOTORS AND MOTOEING 81 
 
 greater obliquity 1 of the propeller shaft. But, notwith- 
 standing these drawbacks, there are many who pin their 
 faith to solid tires, particularly for town use, as the 
 roads are generally fairly good, and the speed rarely 
 exceeds some sixteen miles per hour. An additional 
 advantage may be mentioned, and that is, there is not 
 quite so much skidding with solid tires .as with pneu- 
 matic ones. So, for those who never wish to exceed a 
 most moderate speed with the minimum of tire troubles, 
 particularly if they are not too exacting where their 
 ease in riding is concerned, solid tires, fitted to a light 
 but strong car, built for their use, would be a wise 
 selection. On the other hand, it is not easy for anyone 
 who has once enjoyed the luxury of driving in a good 
 car, suitably fitted with pneumatic tires, to revert to 
 solid ones; indeed, the temptation to run the risk of 
 trouble, and take his chance, seems almost irresistible; 
 but we must be careful not to in any way exaggerate 
 the disadvantages of pneumatic tires, for, in addition 
 to their wonderful resilience, they run, when properly 
 inflated, with less resistance than solids, and if they 
 are, in the first instance, of suitable size 2 and of good 
 quality (as they would be if supplied by any of the 
 famous makers), and proper care is taken of them when 
 in use, 3 also when they are stored or on the wheels of 
 a laid-up car, 4 they may be expected to run some 3000 
 
 1 When the universal joints of the propeller shaft come 
 into use, they cause, or tend to cause, a difference in the 
 uniformity of running of the clutch shaft and driving wheel 
 axle ; that is to say, if the former was running with uni- 
 formity, the latter would be moving with slight variations 
 for each turn of the propeller shaft. 
 
 2 There is a tendency on the part of many makers to 
 keep down the size and weight of pneumatic tires to such 
 an extent that, from the first, they are overloaded. If in 
 doubt as to the size, it is always wiser to err on the right 
 side, and use a tire of ample size and strength. 
 
 3 Refer to footnote on Brakes, page 78. 
 
 4 Rubber commences to deteriorate if exposed to a strong 
 light or high temperatures, or if brought in contact with 
 rust, grease, or most of the acids. So spare tires should be 
 protected from the light, and stored in a place the temper-
 
 83 MOTOES AND MOTOKING 
 
 or 4000 miles before they require replacing (solids, if 
 of the best make, run over twice the distance and cost 
 about half as much) ; of course, the first serious trouble 
 may be due to the inner tubes commencing to perish ; if 
 so, these can be easily and comparatively inexpensively 
 replaced. Every driver of a touring car should be able 
 to repair a puncture, and to lace a leather sleeve gaiter 
 or shoe over the outer cover of a tire and around the 
 felloe of the wheel, should a cover burst on the road. 
 Needless to say, tires which have suffered from bursts 
 should be returned to their makers at the earliest op- 
 portunity, so that the cover may be properly repaired 
 and vulcanized. It is a great mistake to run a car with 
 soft tires, as many are tempted to do, either by the easy 
 running, or to avoid the trouble of pumping up; it 
 means excessive wear and rapid depreciation. They 
 should be inflated until they are just on the point of 
 bulging at the tread under the full load ; this is a better 
 guide than a pressure gauge, as gauges are not always 
 to be relied upon, and after the covers have become 
 worn a given pressure 1 has a different effect upon them. 
 When cars are garaged or stabled for several weeks they 
 should be jacked up, so that the wheels are clear of the 
 ground, and the fabric liners of the tires are not con- 
 tinuously under stress; if this is done, it is not neces- 
 sary to deflate the tires. An occasional wipe with a 
 damp sponge will keep them in condition if they are 
 not exposed to heat and sunlight, as previously ex- 
 
 ature of which does not exceed some 75F. Although tires 
 which have been in use are not so much affected by heat 
 and light as new ones, care should be taken to protect them 
 if the car is laid-up for any time, and to remember that 
 they can only be kept in good condition by washing the mud 
 and dirt off them after every run. In removing the cover 
 from the rim of the wheel, the paint is sure to be more or 
 less injured, and if such exposed parts are not painted 
 again, when an opportunity occurs, with some air-drying 
 enamel, rust will accumulate and injure the tire. 
 
 1 The pressure per square inch varies from about 35 in the 
 tires of the lightest cars to about 110 in those of the 
 heaviest.
 
 MOTOES AND MOTOKING 83 
 
 plained. The covers, inner tubes, and rims require 
 periodical examination for any of the defects that have 
 been referred to. Abnormal wear on the front tires 
 always occurs when the front wheels are not in align- 
 ment with the rear ones, that is to say, when their hori- 
 zontal diameters are not parallel for the position they 
 are in when the car is running forward in a straight 
 line. Any want of such alignment means a combined 
 rolling and sliding, or grinding action, as the wheel 
 passes over the ground. A similar action occurs when, 
 through some defect in the design of the steering gear, 
 or through some straining action, the front wheels do 
 not come to the proper angles which they should make 
 with the front axle when turning a corner. These an- 
 gles are only equal when the car is running in a straight 
 line, but when turning a corner the near-side wheel 
 should be running in a sharper curve than the off-side 
 one for correct running, therefore the gear must guide 
 it into a position, making a smaller angle with the axle 
 than the off-side one does. A very simple and familiar 
 expedient enables the designer to arrange his steering 
 gear to do this; but it is often in the actual construc- 
 tion of the car that such adjustments are apt to be 
 made without sufficient care, although, of course, in the 
 works of the best makers both at home and abroad, so 
 great is the care taken that such parts are little short 
 of perfect when the car is turned out. 
 
 67. Road Wheels. The designer cannot give too 
 much attention to road wheels. These are made of 
 either oak or metal, the former, known as the artillery 
 wheels, being now almost exclusively used, as they wear 
 very well, have a better appearance than the others, and 
 are more easily cleaned. But it can be proved that 
 motor-car wheels, to have a margin of safety equal to 
 that which the wheels of horse-drawn vehicles have, 
 must be many times stronger; in fact, they cannot be 
 too strong for our purpose, as the very lives of motor- 
 ists depend upon the wheels being able to safely with- 
 stand the tremendous strain set up by turning a corner
 
 84 MOTORS AND MOTORING 
 
 at high speed, or by any obstruction that tends to dish 
 them at a time when they are transmitting consider- 
 able power. This is one of the reasons why motor-ear 
 wheels are kept down in size, although it is common 
 knowledge that the larger the wheels, the less power 
 required to drive a given carriage. There are other 
 reasons why large wheels are not used, for they greatly 
 increase the cost of both wheels and tires, and make 
 access to the seats more difficult, whilst they raise the 
 center of gravity of the vehicle, reducing its stability 
 in turning corners. On the ' other hand they run 
 smoother, lick up less dust, and more easily surmount 
 any obstacle. So again we have a compromise. 
 
 68. Balanced Engines. Perfect smoothness of run- 
 ning can only be secured by fitting the car with a well- 
 balanced engine. This would appear to be a very easy 
 matter, as almost every maker of a gasolene engine claims 
 that it .is perfectly balanced, whether it be a single- 
 cylinder one, a two-cylinder, three-cylinder, or whatever 
 number of cylinders it may have. In fact, when bal- 
 ancing is thus referred to, a very loose interpretation 
 of the word is, or should be, intended. The balancing 
 of a reciprocating engine might appear at first to rep- 
 resent the very simple problem which in the single-cyl- 
 inder engine is usually solved by forming weights on 
 the crank arms (as shown in Fig. 1) to balance the re- 
 volving and reciprocating masses; but after this has 
 been done (without going into refinements that would 
 be of interest to an engineering student, but could 
 scarcely be followed by the general reader), there re- 
 main in the vertical engine unbalanced inertia forces, 
 caused by the moving parts, which produce a vertical 
 hammering action. Now, if instead of a single-cylinder 
 engine we consider a two-cylinder engine, with cranks 
 at 180, and reciprocating masses equal, there are cer- 
 tain forces and couples which cannot be balanced, and 
 they result in a tilting effect which tends to rock the 
 engine in a fore and aft direction, and cause serious 
 vibration But with three cylinders, with equal masses
 
 MOTORS AND MOTORING 85 
 
 at the crank radius, and the cranks at 120, the engine 
 can be arranged to run with a more uniform turning 
 action, and with the vertical hammering action practi- 
 cally eliminated, a distinct advantage over the two- 
 cylinder one; but, so far as the rocking action (due to 
 certain unbalanced couples 1 ) is concerned, this engine 
 has little or no advantage over the two-cylinder one of 
 the same power. Now, by adding another cylinder, we 
 get a four-cylinder engine, which gives the designer a 
 much better chance of approximating to a true balance, 
 for with cranks at 180 apart, the usual arrangement in 
 motor-car engines, a perfect fore and aft balance is pos- 
 sible; but the vertical hammering effect can only be 
 imperfectly dealt with, in fact with no more success 
 than in a two-cylinder engine. Notwithstanding this, 
 it cannot be denied that four-cylinder engines are pro- 
 duced which, when run at the speed they were designed 
 to work at, are hard to beat for smoothness of running. 
 But those who have paid attention to these matters will 
 know that to attain the highest possible condition of 
 balance in an engine, five or six cylinders are necessary. 
 Even with the required number of cylinders, the exer- 
 cise of consummate skill in designing the balancing sys- 
 tem is necessary to produce an engine that will run 
 without vibration; indeed, a wealth of mechanical 
 genius has been lavished on the evolution, of the highest 
 form of gasolene engine, and some elegant expedients 
 have been devised in solving the balancing problems. 2 
 So it will be seen that the balancing of engines is a 
 subject on which the man in the street is not likely to 
 be very well informed, in fact, is most likely to be easily 
 misled. 
 
 69. Lubrication. No car can be efficiently run with- 
 out trouble occurring, or even a breakdown, unless it 
 has been constructed in such a way that all the wearing 
 
 1 To keep down the disturbing effect of these couples (the 
 primary and secondary), the cylinders should be placed as 
 near together as practicable. 
 
 " One of the most interesting of which is to be found in 
 the Lanchester engine.
 
 86 MOTORS AND MOTORING 
 
 parts can be easily and properly lubricated. No driver 
 can hope to run his car without trouble, unless he has 
 made a business of mastering the arrangements made 
 for lubricating its various working parts and under- 
 standing the maker's instructions relating to them; in- 
 deed, he should never take a car out without first being 
 sure that everything connected with its lubrication is 
 in order, for, obviously, it is too late to commence to 
 pay attention to such matters when he hears ominous 
 sounds emanating from bearings or rubbing surfaces, 
 that plainly tell him that they are on the point of gall- 
 ing or seizing for want of proper lubrication. New 
 engines in particular require plenty of the best oil, as 
 they are more apt to give trouble until all their bearings 
 have rubbed down to their work. Much ingenuity has 
 been displayed in designing the innumerable forms of 
 lubricators and lubricating devices in common use on 
 cars for securing a regular feed to the various bearing 
 surfaces, with the result that they not only vary with 
 the car, but with different parts of the same car. The 
 most perfect way to lubricate a bearing is to immerse 
 it in an oil-bath, and the more nearly this ideal arrange- 
 ment (which is rarely practicable) is approached, the 
 more satisfactory the result; but a close approximation 
 to this is to be found in the admirable forced or circu- 
 lating-pump lubrication employed on the Maudslay, 
 Mercedes, Wilson-Pilcher, and other cars. In this sys- 
 tem the oil is forced through the bearings, 1 from which 
 it is drained, filtered, and re-used, with the great ad- 
 vantage that it only circulates whilst the engine runs. 
 Ring lubrication also gives a good approximation to 
 it, 2 and in many of the best-known cars the crank-shaft 
 
 1 A fundamental condition for efficient lubrication is that 
 the oil must be fed into the bearing at the slack side. 
 
 2 The bearings are made in such a way that a collar or 
 ring on the shaft, just fitting it and revolving with it, dips 
 into the oil in the well, there being a break in the bearing 
 at its center to allow of this. Of course, with this arrange- 
 ment the oil is being constantly lifted from the well by the 
 ring as it revolves, flowing down from its highest position 
 into the bearing, and back into the well again.
 
 MOTORS AND MOTORING 87 
 
 bearings are fitted with these useful devices, each bear- 
 ing having a lubricating well, which is from time to 
 time supplied with oil from the oil sights on the dash- 
 board, or from an oil reservoir by a hand-pump, as in 
 the Decauville car. 
 
 The important crank-pin bearings are generally lubri- 
 cated by partly filling the crank-chamber with a cylin- 
 der * oil to such a height as to allow the ends of the con- 
 necting rods to dip a little into it, and in so doing lubri- 
 cate the crank-pins each time they come into their lowest 
 position; this causes a deal of splashing, which is inva- 
 riably utilized to lubricate the cylinder by wetting the 
 bottom of the piston 2 and the wall of the lower part of 
 the cylinder. After a time this oil becomes vitiated 
 and requires changing, 3 and it is as well to do this 
 about every 50 or 60 to 100 miles, according to the size 
 of the engine, the smaller ones requiring most frequent 
 attention. The lubrication of most of the other impor- 
 tant bearings is pretty generally performed by a sight- 
 
 lr rhe practice of supplying oil to the crank-chamber in 
 doses, and trusting to its being splashed over the gudgeon- 
 pin and cylinder wall, is the one generally adopted, and 
 although rather haphazard, it seems to work well, but as 
 the oil has to lubricate the cylinder, it must be of good 
 quality, suitable for cylinder use. Sometimes an additional 
 drip lubricator feeds oil to the cylinder wall near the lowest 
 position of the piston, but unless this is forced by some 
 means, a thin oil has to be used, and then, for obvious 
 reasons, it is of doubtful utility. 
 
 *A grooved ring is sometimes fitted into the bottom of 
 the cylinder, so that the oil may accumulate in the groove, 
 and the ring end of the bottom of the piston dip into it, 
 smearing the cylinder wall with oil from it each up-stroke. 
 
 8 This is done by unscrewing a plug at the bottom of the 
 crank-chamber and allowing the oil to escape, the fresh oil 
 being poured into the chamber (till it is about a third full) 
 through a similar hole in its upper part. It is necessary 
 to occasionally wash out the chamber with paraffin to keep 
 it clean ; and to prevent an excess of oil accumulating in 
 the chamber, an overflow pipe is sometimes fitted, as, 
 should the chamber become too full, too much oil is apt to 
 find its way into the cylinder and lodge between the points 
 of the sparking plug, impairing ignition.
 
 88 MOTORS AND MOTORING 
 
 feed lubricator, which should be regulated not so much 
 for a large supply, but for a certain and continuous 
 flow. In some of these lubricators all the tubes are 
 governed by one tap, which is the only one that requires 
 opening and shutting, the others having been once ad- 
 justed for the feed required in each case. Needless to 
 say, the efficiency of this system largely depends upon 
 the tubes being kept clean and free from obstructions. 
 In many cars lubrication is effected by an automatic 
 positive feed arrangement, the oil distribution com- 
 mencing automatically when the engine is started, and 
 ceasing when stopped, no turning on or off being re- 
 quired. An interesting example of this type is fitted 
 to the Lanchester cars, where the bottom of the oil- 
 tank is made to fit a spindle running longitudinally 
 through it, so that the upper part of the spindle is in 
 communication with the bulk of the oil, whilst the 
 lower half is opposed to a series of outlets which com- 
 municate with the various parts to be lubricated. The 
 spindle, which is rotated by a worm-gear from the half- 
 speed shaft, has a series of pockets or depressions cut 
 in it one opposite each outlet so that in rotating 
 these pockets first fill with oil from the tank, and after- 
 wards discharge their contents into the various pas- 
 sages for distribution. 
 
 In some systems of lubrication provision is made to 
 prevent the flow of oil being affected by cold weather. 
 Thus in the fine Crossley car, the oil is forced from the 
 main tank by exhaust pressure 1 to water-heated sights 
 on the front of the dashboard, the oil being thus kept 
 warm, and its flow constant at all temperatures of the 
 atmosphere. 
 
 Change-speed gears generally run in thick oil, 2 the 
 
 1 In the James and Browne lubricator, oil is supplied from 
 the tank through sight-feed glasses, by pressure derived 
 from an induced vacuum on the crank-chamber. 
 
 1 Grease is sometimes used for this purpose, but if this 
 be too viscous to flow, the wheels cut for themselves races 
 in the body of the stuff in which they revolve, niore or less
 
 MOTOES AND MOTOEING 89 
 
 gear-case being occasionally partly filled with it, after 
 drawing off the old and dirty oil. The more out of 
 sight a bearing may be, or the smaller the amount of 
 motion in it, the more likely it is to be neglected, as, 
 even if it works dry, the feeble squeaking noise it makes 
 is often unheard. This particularly applies to parts 
 which are ordinarily lubricated with the common oil- 
 can, such as the regulating mechanism, the valve-rod 
 thrust bearing, lever hinges and the steering gear, which 
 require regular attention. Even the leaves of the springs 
 require occasional greasing, 1 or they will grind on one 
 another and become noisy. On many cars Stauffer 
 grease-boxes are fitted to some of the minor parts ; these 
 require screwing up about an eighth of a turn for every 
 60 to 100 miles run. The advantage of this arrange- 
 ment is, that should a bearing run hot, the grease melts 
 and flows over the journal. 2 Beginners usually err on 
 the side of using far too much oil, 3 but this is a fault 
 on the right side, and with any given car only experi- 
 ence with close observation will teach its driver how to 
 judiciously use an expensive material, and keep his 
 mount in the pink of running condition. After a time, 
 the temptation with some to take liberties with the car 
 is great, and they may even run it a whole day without 
 attending to its lubrication, but such a liberty as this 
 cannot be taken every day without at least serious de- 
 preciation occurring. 
 
 70. Lubricating Oils for the cylinders must be of a 
 
 from contact with the lubricant. The same thing occurs 
 with oils that solidify at temperatures that can hardly be 
 considered low. In the best practice, the bearings in the 
 gear-case are independently lubricated, as the oil in the 
 case becomes charged with metal dust and small chips 
 from the wheels. 
 
 1 This is done by jacking up the frame till the leaves of 
 the spring can be separated a little by a screwdriver, when 
 grease is introduced with a knife. 
 
 2 The part of the shaft or spindle which runs in the 
 bearing. 
 
 8 About one gallon per thousand miles appears to be a 
 fair allowance for a good-sized car.
 
 90 MOTORS AND MOTORING 
 
 kind specially suitable for use at high temperatures, 
 therefore we are precluded from using vegetable and 
 animal oils for this purpose, as they partially decom- 
 pose at high temperatures, liberating fatty acids, and 
 forming pitch. But mineral oils stand heat much bet- 
 ter, and are, therefore, exclusively used for cylinders, 
 and also, as a matter of fact, for most engine lubrica- 
 ting purposes. 
 
 High-class cylinder oils are very expensive; their 
 manufacture is in the hands of a very few, and the 
 poor motorist, who must have the best if he is to be 
 economical, must patiently wait for some relief till the 
 Macalpine process is commercially worked on a fairly 
 large scale. 
 
 Needless to say, the many secondary bearings about 
 a car can be efficiently lubricated by a high-class heavy 
 machinery oil, but it is best to follow the advice of the 
 maker in these matters. The preparation and use of 
 grease has been referred to in the article on Chains, and 
 need not be further touched on. Other matters relat- 
 ing to lubrication have also been explained in various 
 connections, and are therefore not mentioned in this 
 article, which could be profitably much extended if the 
 exigencies of space would permit. 
 
 71. Fuel Efficiency of the Car. We have seen in 
 Article 23 that all the energy of the fuel we can expect 
 to get in the form of work at the crank-shaft is 15 
 per cent., but there are further serious losses, due to 
 friction, before power is available at the driving wheels. 
 Thus we must expect a loss of about 15 per cent, from 
 crank-shaft to propeller-shaft through the friction in 
 the gear-box, and a further loss of, say, 20 per cent, 
 from propeller to cross-shaft after the bevel wheels 
 have worn a bit, and a still further loss of 15 per cent, 
 from the cross-shaft to the road wheels through the more 
 or less dirty chains; this of course means that the total 
 , 85X80X85X15 rt _._, CH 
 efficiency may be looxlooxlooxloo =0867, or 8-6T 
 
 per cent., or only a little more than one-twelfth of the
 
 MOTORS AND MOTORING 91 
 
 potential energy of the fuel is available as useful work 
 at the tires of the driving wheels. 
 
 72. On Selecting a Car. The great motor car exhi- 
 bitions never fail to attract numbers of intending pur- 
 chasers. Not a few of these having formed ideas as to 
 what they want, they have decided upon the sum of 
 money they will lay out, the form and general arrange- 
 ment of the tonneau, and perhaps even its color, the 
 number of cylinders and approximate power of the 
 engine have been settled, whilst the kind of transmis- 
 sion, the ignition, lubricating and cooling systems, and 
 the many other important features their ideal car is to 
 have, have been thought out; but, after a painstaking 
 tour of the stands, the potential motorist will find the 
 nearest approach to his requirements is a compromise, 
 as, indeed, every car is; but there is generally on any 
 well-known car some particular feature that is more 
 perfect in its way than that on others in the market, 
 and this is often why a certain car is selected in prefer- 
 ence to others. Of course, if this feature is a really 
 important one, one that represents higher efficiency, 
 increased simplicity or greater durability, then the selec- 
 tion may be a very judicious one, but if, on the other 
 hand, it is merely the form, or even the color and finish 
 of the body, as perhaps it more often is than some pur- 
 chasers would willingly admit, the least said about the 
 matter the better. Not so very long ago it was far 
 from an easy matter to select a satisfactory American 
 made car, but fortunately that is not the case now, as 
 cars more perfect in design, materials, workmanship, 
 construction, finish, and durability are not to be found 
 anywhere in Europe than those which are turned out 
 by our most famous makers. And this can be safely 
 said whilst bearing in mind and duly appreciating the 
 splendid vehicles that have been and are being con- 
 structed abroad, more particularly those which owe their 
 development to French, English, and German genius. 
 
 73. Car Driving. The principal makers of cars and 
 motor cycles supply their customers with printed par-
 
 92 MOTORS AND MOTORING 
 
 ticulars of all the important details of their vehicles, 
 and, in addition, very concise driving directions; they 
 also, as a rule, willingly allow purchasers to spend a 
 few days in their works to enable them to become ac- 
 quainted with the internal economy of the mounts they 
 purchase. This is a privilege that everyone should 
 avail himself of, even if he employs a professional 
 driver, as it is only by getting a good grasp of how 
 everything is arranged in a car, and of how the prin- 
 cipal adjustments and connections are made, in fact, 
 by learning the functions of every detail of the mech- 
 anism of his car, that he will in time become independ- 
 ent of a driver's company or assistance, when such is 
 not desired, and be able to detect any attempt to impose 
 where repairs are concerned. A purchaser should 
 always arrange with the maker for a few lessons in 
 driving, and for one or two long runs; he will then be 
 taught the use of the various handles, levers, fittings, 
 and accessories used by the driver in running the car, 
 and will be shown how the speed of the engine can be 
 varied by advancing and retarding the spark, also by 
 varying and throttling the mixture, and by a combina- 
 tion of these. The ignition system will be explained, 
 and he will be shown how the accumulators are tested 
 and the current switched on and off. The lubricating 
 system will be carefully traced out, and he will learn 
 what to do, so that in starting the car everything that 
 requires it will be properly lubricated, whilst the use 
 of the clutch and accelerator will be made clear, and 
 the action of the cooling system gone into. After the 
 owner has been through all this, he will be taken out 
 for a trial spin on some quiet road, or perhaps in one of 
 the parks early some morning, and he will be able to 
 get a little actual driving practice, at first with the car 
 running on its lowest speed : he will then soon find that 
 there is much to learn before he can with any confidence 
 steer the vehicle, manipulate the clutch, and apply the 
 brake to stop the car with the skill required to avoid 
 sudden strains and shocks. After he has shown some
 
 MOTORS AND MOTORING 93 
 
 proficiency in these matters, he will be taught how to 
 change the gear from a low one to a higher, and from a 
 high one to a lower, without injuring the teeth of the 
 wheels; he will be warned against trying to reverse the 
 car by changing the gear before it has been brought 
 to a standstill. But all this time he may have been 
 merely doing the fancy work (which can be mastered 
 in a very short time), his instructor controlling the 
 running of the engine by advancing or retarding the 
 spark and regulating the throttle, operations that he 
 will, after the first two or three lessons, soon begin to 
 perform with a fair amount of readiness. Only experi- 
 ence of this kind will enable him to master the art of 
 driving in such a way that he almost instinctively knows 
 what to do the instant any adjustment is required. It 
 is hardly necessary to remark that the qualities neces- 
 sary to make a good driver are not possessed by every- 
 one, but it is simply astonishing to find that so many 
 possess an instinctive aptitude for motoring. They are 
 soon able, without any previous mechanical training, to 
 skillfully manipulate their car, and intelligently diag- 
 nose the cause of stoppage, and if they have nerve and 
 presence of mind, they are equipped by nature to enjoy 
 to the full a delightful pastime, for there is a peculiar 
 and indescribable pleasure in feeling that you have at 
 your command an obedient agent that will instantly 
 respond to your slightest command, and, should your 
 car be a fairly powerful one, carry you up the steepest 
 hill with a rush that must be experienced to be appre- 
 ciated; indeed, the only rational excuse for using a 
 powerful car is to be able to negotiate hills at the legal 
 limit speed, and to rapidly accelerate speed after slow- 
 ing down or stopping; but this very power is one that 
 is too often abused by unskillful owners and inconsid- 
 erate and careless drivers, particularly in the abnormal 
 use of the main brakes, which are worked by the side 
 hand lever, which is really an emergency brake, one 
 that should only be used when it is necessary to pull the 
 car up very short to avoid an accident ? and it can never
 
 94 MOTOBS AND MOTOEING 
 
 be effectively used without the tires in particular suf- 
 fering. A skillful and careful driver always assumes, 
 on approaching a cross-road, that something is about to 
 move out of it that might come in his way, or in near- 
 ing a bend or turn in the road that there is a flock of 
 sheep approaching, or something of the kind blocking 
 the way; he then slows down enough to enable him to 
 pull up the car in time, by instantly but gradually ap- 
 plying the foot-brake. It will be seen that all this really 
 represents organized common sense; it means that a 
 reliable good car can be driven for years with little de- 
 preciation, and the annual expenditure of a compara- 
 tively small amount on repairs and up-keep, if it is 
 carefully and cleanly kept in running condition, all 
 bolts and nuts liable to work loose being examined, and 
 screwed up when necessary after each trip, due atten- 
 tion being paid to lubrication, and the car itself driven 
 with a sympathetic consideration for its powers of en- 
 durance. On the other hand, it means that if the car 
 is roughly used, the teeth of the gear wheels may be 
 stripped, many parts severely strained, and the driving 
 tires practically destroyed in a very few minutes. 
 
 It should not be overlooked that in locomotive prac- 
 tice a man has to spend years in qualifying to take 
 charge of an engine, and even then he is not competent 
 to execute repairs, nor is required to do so; and in 
 almost every case, unless a motor-car driver be a trained 
 mechanical engineer, or at least has had some good 
 workshop experience, it is false economy to allow him 
 to even take up brasses and do such jobs ; as to perform 
 them satisfactorily no small amount of skill is required. 
 It would not be going too far to say that the least im- 
 portant part of the training of a driver is that which 
 enables him to take charge of the wheel and skillfully 
 steer a car through crowded traffic. The really profi- 
 cient man is able to detect the slightest thing abnormal 
 about the running of a car, and locate its cause before 
 anything serious occurs. And if his training has been 
 of the right kind, and he takes a pride in his work, he
 
 MOTOES AND MOTOKING 95 
 
 will keep his car so that everything about it is in the 
 pink of condition, and screwed up to concert pitch 
 when required for use. 
 
 74. How to Start a Car. As some reader may 
 become possessed of a second-hand * car, and therefore 
 will not be in so fortunate a position, so far as tuition 
 is concerned, as the owner of a new car, it will be as 
 well to very briefly explain what is usually done in 
 starting the engine and car. But as much information 
 bearing on driving has been given in the articles on 
 Ignition, Cooling, Gear-changing, Carburation, and 
 Carburettors, etc., the references to these matters will 
 be very brief. The first thing that may be done, is to 
 see that the tanks are filled with enough gasolene and 
 water for the purposed run, and then make sure that 
 all the working parts are thoroughly lubricated, and 
 that the sight-feed lubricators are adjusted. Next turn 
 on the gasolene to supply the carburettor, and flood the 
 latter by moving the float-needle up and down two or 
 three times, fully opening the mixture throttle, push on 
 the electric switch, and retard the ignition to prevent 
 back-firing; then place the change-speed lever in the 
 neutral position, and smartly turn the starting handle 
 till the explosions drive the engine, being careful always 
 to exert the effort in pulling the handle upwards, and 
 refrain from pushing it downwards, as, should back- 
 firing accidentally occur whilst it is being pushed down, 
 
 1 No one who is not an experienced mechanical engineer 
 should be tempted to buy a second-hand car without the 
 advice of an expert, as the art of the horse dealer in doctor- 
 ing a horse is not to be compared with that which is some- 
 times practiced in preparing old-fashioned, or even obsolete, 
 cars for sale. In many cases, too, modern cars that have 
 been very badly treated, and whose mechanisms are prac- 
 tically worn out, are made to look like new ones, to say 
 nothing of the freaks which are faked. On the other hand, 
 excellent cars can be picked up sometimes at less than half 
 their original cost, as some owners are never long satisfied 
 with their vehicles, and must have a new one at least once 
 a year.
 
 96 MOTOES AND MOTOKING 
 
 it would be violently and suddenly forced upwards, with 
 almost certain injury to the arm. The clutch-pedal 
 may now be depressed, and the gear-lever pulled over 
 till the gear for the first speed * is in mesh, and the 
 latch of the lever slips into its notch in the quadrant, 
 when the clutch may be gently let in to allow the car 
 to gradually accelerate its speed. (Eefer to Article 61.) 
 
 CONCLUDING REMARKS 
 
 75. In looking over the contents of this little work, 
 the author is forcibly reminded that many matters 
 which could not fail to interest the motor novice have 
 been omitted owing to the want of space. This being 
 so, brief reference to some of the more important omis- 
 sions may be made in this concluding article. 
 
 One of the qualities of a car which does not generally 
 receive the attention it deserves is ACCESSIBILITY; it 
 is true that much has been done to improve cars in 
 this direction during the past year or two, but, although 
 it is quite the exception to find engines whose valves 
 are not readily accessible, the same thing can scarcely 
 be said for clutches, which should always be arranged 
 so that an adjustment is easily made; and many other 
 parts, such as gear-cases, differentials, etc., should be 
 get-at-able in the sense that they can be taken out for 
 repairs without dismantling half the car; and,, more 
 particularly, in every case those parts which periodically 
 require adjusting, or occasional attention on the road, 
 should be as accessible as possible. In some cars the 
 driving and controlling fittings are not placed so that 
 they can be worked with ease by drivers whose arms 
 and legs are of average length; this is particularly the 
 case with push pedals, which might with advantage be 
 
 1 Needless to say, the novice should wait till he is pro- 
 ficient in driving on the lowest speed before he attempts to 
 run his car on a higher one.
 
 MOTOES AND MOTOBING 97 
 
 made adjustable, as (spinal columns being fairly con- 
 stant in length) the difference between a tall person and 
 a short one is mainly one of legs. RELIABILITY is a 
 quality the importance of which cannot be overrated, 
 and the various reliability trials here and abroad, 
 arranged so that absolutely every replenishment, ad- 
 justment, and cleansing of the cars was done on the 
 road, under official observation in the running time, 
 have enabled the judges to draw up reports that have 
 greatly assisted designers and makers,, and have led to a 
 high standard of reliabilty being reached. And the 
 same remarks equally apply to the highly successful 
 light car trials recently made. 
 
 The question of dust-raising by motor cars has been 
 studied and the results of the experiments now being 
 made are sure to be of great interest to motorists. 
 It has been noticed, in a general way, that cars which 
 have a clean nnderbody without any projections, the 
 lowest parts at the back being higher than those at the 
 front, the bottom forming a taper clearance, raised 
 the least amount of dust at a given speed. It has also 
 been noticed that the amount of dust raised increases 
 with the size of the tires, other things being the same, 
 and that exhausts impinging on the ground increase 
 the evil; but, fortunately, these are matters that we 
 shall know more about soon, and, if some simple means 
 of mitigating what is fast becoming a grave nuisance, 
 both to motorists and other users of our roads, can be 
 devised, it will be hailed as a great boon. Of course, 
 whatever can be done in this direction will only partly 
 solve the problem, the real solution of which is the mak- 
 ing of waterproof roads. But if such roads were once 
 made and used only by automobiles, there would be 
 comparatively little depreciation; as it is, on ordinary 
 roads, the tires lick up and disperse the road detritrus 
 (rubbish of attrition), and in so doing accelerate the 
 disintegration of the surface; but, of course, the injury 
 done in this way is slight compared with the hammer- 
 ing effect of horses' feet on the metaling, which sooner
 
 98 MOTOES AND MOTOKING 
 
 or later destroys the surface, whatever it may be made 
 of. It is not easy to foresee how this road problem is 
 to be ultimately solved, but if motorists continue to 
 increase in number at the present rate, they will ere 
 long be strong enough to influence for the common 
 good those bodies who are responsible for the up-keep 
 of our roads. 
 
 STEAM CARS have been greatly improved during the 
 past two or three years, and when their principal points 
 are compared with those of gasolene cars, it is not easy 
 to understand why the former should be so much neg- 
 lected by the motorist. 1 It is true they did not at one 
 time compare very favorably with the gasolene car; 
 boiler 2 troubles were frequently heard of, particularly 
 in cases where boilers which required skillful handling 
 were in the hands of careless and inexperienced drivers. 
 Then, again, fuel-consumption was usually excessive, to 
 say nothing about the difficulty of getting a supply of 
 suitable water two or three times on a long run. But 
 all that is a matter of the past, and the modern steam 
 car of the best make can be driven a distance of over 
 a hundred miles without a stop for water or fuel, and 
 with no more attention than is required by the most per- 
 fect gasolene car, whilst by using the throttle the range 
 of engine power is so great that no change-speed gear is 
 required, and the condensation of steam is so complete 
 that the exhaust is rarely seen. In addition to these 
 good features, the steamer is a splendid hill climber, 
 and its smooth vibrationless running on a decent road 
 is what many acclaim to be the poetry of motion. 
 Indeed, if, in selecting a car, absence of vibration, for 
 some reason or another, is considered the most impor- 
 tant factor, then it would be a safe plan to paraphrase 
 the famous whist injunction "When in doubt, select 
 a steamer," and a selection could safely be made from 
 
 1 Refer to Article 2, where it will be seen that the 
 variety of steam cars is small compared with gasolene ones. 
 
 a Makers prefer to call these steam generators, or, briefly, 
 generators.
 
 MOTOES AND MOTORING 99 
 
 the foreign Miesse, or Serpollet, 1 or the American 
 White, to mention only three of the best known. 
 Doubtless, ere long, more attention will be paid to the 
 relative merits of the two systems, but, for the nonce, 
 everyone knows that, rightly or wrongly, the gasolene car 
 is an easy first favorite, and the fundamental fact that it 
 is more economical to burn the fuel in the cylinder of the 
 engine than in a boiler will always be in its favor, not- 
 withstanding its drawbacks and the possibilities of 
 trouble in connection with carburettors and ignition 
 systems. 
 
 Should the day-dreams of some of our advanced 
 thinkers ever eventuate in the creation of a gasolene tur- 
 bine of great range of power and moderate weight, it 
 is safe to say that a new era in automobilism would 
 rapidly dawn. But even taking things as they are, it 
 is possible for any man who can afford to keep a dog- 
 cart, to run a light car and bring a new joy into his 
 life, with little or no additional expense, if he is 
 mechanically inclined, and is not afraid of attending 
 to the car himself. 
 
 1 Mons. Serpollet has perhaps done more than any man 
 living to develop the possibilities of the steam car. Indeed, 
 it can be safely said that what he does not know about 
 flash boilers it is not worth knowing.
 
 INDEX 
 
 Accelerator, 56 
 Accessibility, 96 
 Accumulators, 38 
 
 Charging, 45 
 
 Charging from Electric 
 Batteries, 45 
 
 Charging from Electric 
 Mains, 46 
 
 Efficiency of, 48 
 
 Internal Resistance of, 48 
 
 Rate of Charging and Dis- 
 charging, 47 
 
 Spare, 48 
 Adjustments, 96 
 Air, Auxiliary, 21 
 Air, Composition of, 31,' 
 Air-Cooled Cylinders, 58 
 Air Fans, 61 
 Air Locking, 61 
 Air required for Carbura- 
 
 tion, 32 
 
 Alcohol, Denaturized, 30 
 Ammeter, The, 47 
 Ampere, The, 40 
 Automobile Club of America, 
 
 . Reference to, 77 
 Auxiliary Air, 21 
 
 Back-Firing or popping, 53, 63 
 
 Balanced Engines, 83 
 
 Balancing Single Cylinder En- 
 gine, 84 
 
 Two Cylinder Engine, 84 
 Three Cylinder Engine, 84 
 Engines with four or more 
 Cylinders, 85 
 
 Ball Bearings, 78 
 
 How to adjust them, 79 
 Renewing them, 79 
 
 Batteries, 38 
 Primary, 39 
 Secondary or Storage, 38 
 
 Bearings, Ball v. Plain, 78 
 Lubrication of, 79 
 
 Beau de Rochas, or Otto 
 Cycle, 8 
 
 Benzine, 30 
 
 Benzol, 30 
 
 Blake, Mr. F. C., Reference 
 to, 42 
 
 Bollee Car, Reference to, 55 
 
 Brakes, 76, 77 
 
 Emergency or Auxiliary, 
 
 76, 77 
 
 Burning Point of Gasolene, 29 
 By-Pass for Muffler, 63 
 
 Canstatt Daimler Car, Refer- 
 ence to, 73 
 Carburation, 16 . 
 Carburettor, Hot Jacket for, 
 
 18 
 
 Kreb's, Reference to, 23 
 Longuemarre, Reference 
 
 to, 20 
 
 Stoppage in Nozzle, 21 
 The De Dion Surface, 24 
 The Float-Feed or Spray, 
 
 The Surface, 24 
 Carburettors, Fundamental 
 Condition for Perfect 
 working, 23 
 
 Cardan Shaft and Joints, 67 
 Chain Driving, 75 
 Chains, Cleaning and Lubri- 
 cating them, 76 
 Varying Tightness of, 80 
 Charge Volume Throttling, 55 
 Chassis, Definition of, 2 
 Clearance Space, 10 
 Clutch, The, 69 
 Fierce, 70 
 
 Fitting the Leather, 70 
 How to Adjust, 70 
 Leather Dressing, 71 
 Letting it in, 77 
 Loss of Power due to Slip, 
 
 70 
 Nursing of In Mounting 
 
 Hills, 56 
 Collan Oil, 71 
 
 Combining Proportions of C 
 and O, and H and O, 
 31 
 
 Proportions of Illuminat- 
 ing Gas and Air, 17 
 Combustion, Air required for, 
 
 31 
 Commutator, 42 
 
 Panhard Type, 54 
 Contact Breaker, 42 
 
 101
 
 102 
 
 INDEX 
 
 Controlling by Throttling the 
 
 Mixture, 55 
 Cooling Efficiency, upon what 
 
 it depends, 58 
 
 Crossley Car, Reference to, 88 
 Crossley, Messrs., Reference 
 
 to, 88 
 
 Cylinder Cooling, Forced Cir- 
 culation System, 66 
 Cooling, Thermo-Syphon 
 
 System, 60 
 
 Cooling System, Rubber 
 Hose Connections, 60 
 Wall, Temperature of, 58 
 
 Davy Lamp, 30 
 
 Dead Centre of Crank, 7 
 
 Decauville Car, Reference to, 
 87 
 
 De Dion Car Surface Carbu- 
 rettor, 24 
 Sparking Plug, 43 
 
 Differential Explanation of 
 
 Principle of Gear, 69 
 Shaft, 75 
 
 Distance Rod, 75 
 
 Dressing for Clutch Leather, 
 
 Drivers' Training, etc., Re- 
 ferred to, 94 
 
 Duryea Car, Reference to, 55 
 Dust Raising Nuisance, 97 
 
 Earth Wire, 44 
 
 Efficiency, Fuel of the Engine, 
 
 Mechanical, of Engine, 33 
 Electric Ignition, 35, 37 
 Electro-Magnetic Ignition Re- 
 ferred to, 37 
 Electro-Motive Force, 40 
 Engines, Balancing, Various, 
 
 84 
 
 Balancing, Primary and 
 
 Secondary Couples, 85 
 
 Unbalanced Inertia Forces, 
 
 '84 
 Epicyclic Gear, Reference to, 
 
 Excellence of American Cars, 
 91 
 
 Exhaust Gases, Objectionable 
 
 Odour, 30 
 
 In relation to Dust Rais- 
 ing, 97 
 
 External Plug Gap, 43 
 
 Foot-brake, 73, 76, 77 
 Fuel Efficiency of a Car, 90 
 
 Efficiency of Engines, 34 
 
 The, 28 
 
 Other than Gasolene, 30 
 Fuller's Earth, 70 
 
 Gasolene, 28 
 
 Its disadvantages, etc., 29 
 Straining and Filtering, 28 
 
 Gear- Box, 65 
 
 Gear Changing, 73 
 
 Gillet-Foust Motor, Reference 
 to, 57 
 
 Governing and Controlling, 49 
 On the Exhaust, 50 
 On the Inlet, 49 
 On the Throttle, 49 
 
 Governor, Centrifugal, Refer- 
 ence to, 55 
 
 Grease Box, Stauffer, 89 
 
 Grinding in Valves, 15 
 
 High-Tension Ignition, 37 
 Hooke, Dr., Reference to, 67 
 Horse-power, 32 
 
 Brake, 33 
 
 Indicated, 33, 51 
 How to Start a Car, 95 
 
 Ignition, 35 
 
 Advancing and Retarding, 
 50 
 
 Late, 52 
 
 Pre-, 52 
 
 Tube, 35 
 Indicators, 51 
 Induction Coil, 41 
 Internal Combustion Engine, 
 
 Interrupter, 44 
 
 James and Browne Car, Ref- 
 erence to, 88 
 
 Kreb's Carburettor, Reference 
 to, 23 
 
 Lampblack for coating Con- 
 ducting Surfaces, 61 
 
 Lanchester Car, Reference to, 
 85, 88 
 
 Late Ignition, 52 
 
 Leaky Valves, 14 
 
 Lenoir Engine, Reference to, 
 
 Letting in the Clutch, 76 
 Live-Axle or Cardan Drive, 67 
 Longuemarre Carburettor, 
 
 Reference to, 20 
 Lubricating Chains, 76 
 
 Ball Bearings, 79 
 
 Springs, 89 
 Lubrication, 85 
 
 Automatic Positive Feed, 
 88 
 
 Forced, 89 
 
 Oils, 89
 
 INDEX 
 
 103 
 
 Lubrication, Replenishing 
 
 Crank-Chamber, 87 
 Sight-feed, 87 
 Vitiated Oil, 87 
 Water-heated Sights, 88 
 
 Manograph, Hospitalier-Car- 
 
 pentier, 51 
 
 Maudslay Car, Reference to, 86 
 Mechanical Efficiency of En- 
 gine, 33 
 Mercedes Car, Reference to, 
 
 73, 86 
 
 Miesse Car, Reference to, 98 
 Mixture, Richness of, 20 
 Mors Car, Reference to, 54 
 Motor Car, Elements of, 80 
 
 Definition of, xi 
 Mufflers, Principle of, 62 
 
 By-Pass, 63 
 
 Typical Examples, 62 
 
 Nobel, Reference to, 31 
 
 Odour of Exhaust Gases, xi 
 Ohm, The, 40 
 Oil, Collan, 71 
 
 For Cylinder Lubrication, 
 
 Otto Cycle, 7 
 
 Panhard Clutch, 71 
 Petroleum, Fractional Distil- 
 lation of Crude, 28 
 
 Spirit, 28 
 
 Plug-Gap, External, 43 
 Popping or Back-Firing, 63 
 Pre-Ignition, 52 
 Primary Batteries, 39 
 Pump, Centrifugal, 59 
 
 Gear, 59 
 
 Rotary force, 59 
 
 Radiators, Multitubular v. 
 
 Coil, 60 
 Best kind of Surface for, 
 
 Refining Tallow, 76 
 
 Reliability, 97 
 Trials, 97 
 
 Roads, Waterproof, 97 
 
 Road Wheels, 83 
 
 Alignment of, 83 
 Artillery v. Wire, 83 
 Factors which decide 
 size, 84 
 
 Scavenging, 12 
 
 Second-hand Cars, Precau- 
 tions in Buying, 95 
 Selecting a Car, 91 
 Serpollet Car, Reference to, 98 
 
 Skidding, 78, 81 
 
 Spare Accumulators, 48 
 
 Sparking Plug, 43 
 
 Specific Gravity, 34 
 
 Springs, Special, for Solid 
 
 Tires, 80 
 Lubricating, 89 
 Sprocket Wheels, 75 
 Starting Handle. How to use 
 
 it, 95 
 
 Stauffer Grease Boxes, 89 
 Steam Cars v. Gasolene Cars, 
 
 Steering Gear, 83 
 Stretcher Bar, 75 
 Switch, The, 44 
 
 Tallow Refining, 76 
 Temperature^ g of Cylinder 
 
 Testing on a Closed Circuit, 48 
 Thermo -Syphon System of 
 
 Cylinder Cooling, 60 
 Throttling the Mixture, 55, 76 
 Tube Ignition, 35 
 Tires, Abnormal wear of, 
 
 Front ones, 83 
 Effect of Light, Dirt, 
 Rust, and Grease, 81 
 Fixing Solid ones, 80 
 Inflating, 82 
 Inner Tubes, 82 
 Size in Relation to Dust 
 
 Raising, 97 
 Skidding, 78, 81 
 Soft, 82 
 
 Solid v. Pneumatic, 80 
 Treatment of Burst Ones, 
 
 Treatment of, when Laid 
 up, 82, 83 
 
 Universal Joints (Hooke's or 
 Cardan's), 67, 81 
 
 Valves, Automatic Inlet, 11 
 
 Grinding in, 15 
 
 Leaky, 14 
 
 Lifter, 16 
 
 Mechanically Operated In- 
 let, 12 
 
 Volt, The, 40 
 
 Voltage of the Current, 47 
 Voltmeter, The, 47 
 
 Water-cooled Cylinders, 59 
 Water-logged Float, 21 
 Watt, The, 41 
 Wheels, Road, 83 
 White Car, Reference to, 98 
 Wilson-Pilcher Car, Reference 
 to, 86
 
 TL 
 
 45 
 
 THE LIBRARY 
 UNIVERSITY OF CALIFORNIA 
 
 Santa Barbara 
 
 THIS BOOK IS DUE ON THE LAST DATE 
 STAMPED BELOW.
 
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