MOTOR VEHICLES

the greatest industrial development of the first quarter of the 20th century was. that of the motor road vehicle. development of the self-propelled, petrol-engined vehicle began in germany in the eighties with the work of daimler and benz, and was carried forward particularly energetically in france for more than a decade, from 1895 on. i, history of motor vehicles about 1910 the united states assumed the leadership in the production of this type of vehicle. transport and other con- ditions naturally favoured the use of motor vehicles there. american manufacturers cut down their production costs materi- ally below those in europe, in spite of the higher wages pail by them, and thus sold their cars at very reasonable prices. by 1925 more than one half of all the families in the country had their own car and more than 83°, of all the cars in the world were owned in the united states. registration figures showed that on jan. 1 1926, there was one vehicle to every 5-7 persons in the whole country, while in california, the state with the greatest ‘‘ motor density,” there was one to every 2-8 persons. nmotor-vehicle manufacture had become the greatest manufactur- ing industry in the country, in point of value of output. econonuic reasons.—while the world war accelerated pro- duction of motor-cars in the united states and retarded it in those european countries which were engaged in the conilict from the start, the chief reasons for the pre-eminence of the united states as a motor-using country are of an economic nature. america is a land of magnificent distances; in many sections towns and cities are far apart, and long trips must often be made over the public roads, for which purpose horse vehicles are quite unsatisfactory. petrol (in the united states called gasolenc), the fuel commonly used for motor vehicles, is a native product, comparatively cheap and plentiful. the per capita wealth is greater than in most countries and well distributed. not all conditions were favourable to the introduction of motor-cars, however. the industrial countries of europe had magnificent systems of hard-surfaced roads, which were practi- cally non-existent in the united states at the beginning of the ‘motor era. this, though a handicap, did not prove a serious obstacle. in the early years of motor-car development the pri- vate passenger car was generally regarded as a means of pleasure, and in europe this remained its chief function. but in the united states and canada (where the proportion of motor-cars to popu- lation was not much less than in the united states) it became a great factor in business life. in new york city, for instance, a very large proportion of the street traffic in 1925 was by motor, and in the main thoroughfares horse vehicles were almost a rarity. such agricultural states as iowa and nebraska had rela- tively more cars than the industrial states, and the farmers used their cars chiefly for business purposes. as the substitution of the motor-car for the horse came about gradually, it did not greatly impress the general public; nevertheless, it profoundly influenced modern life. bus and jitney services.—in the citics of the united states the once familiar horse cabs and hansoms had disappeared before the motor-propelled taxicab by 1925. numerous bus services competed with the tram services, particularly in outlying districts, and even cut heavily into the local passenger busi- ness of the railways. about 1915, many owners of private cars began carrying passengers in competition with tram lines, their vehicles being known as jitney buses (jitney, a russian coin about equal in value to five cents, then the common tram fare). these jitneys did much business, especially during the “ rush ” hours when people go to work and return home, as their pas- sengers avoided the crowding of the street-cars and the annoy- ance of frequent stops. in some sections of the country conditions were made rather hard for the jitney owner by legislation, and the business shrank or ceased entirely; while in others, and particularly in detroit, it was still thriving in 1926. freight haulage-—motor-trucking and the haulage of freight by motor vehicle began to assume importance in the united states only about 1910. this branch of the industry up to then motor vehicles had been more successful in great britain and germany. from 1910, however, it consistently increased in the united states, where under war conditions the motor-lorry even entered into competition with the railways. an enormous amount of motor freight traffic grew up over certain routes between important industrial cities, as between detroit, mich., and toledo, o., and between akron and cleveland, ohio. one large tire manu- facturing company in akron, o., with cotton mills in boston, mass., over 600 m. away, established a fast freight service, be- tween these two cities, of motor-trucks on pneumatic tires. some of this development was evidently due to the abnormal conditions which made railway freight service inadequate during and immediately after the world war. military operations gave a great impetus to motor-truck development. in addition to the urgent demand for trucks for military purposes there was also a strong demand for business purposes, owing to the intense industrial activity and to the breakdown of the railways under the war strain. advantages.—the substitution of the motor-car for the horse was beneficial in various ways. in the first place the car is much more specdy and more comfortable for transport. with a motor- car a physician, for instance, can extend his practice over a much wider territory; contractors can oversee more thoroughly a num- ber of projects under way at the same time; stores and factories can deliver goods in the country, at distances of 30 m. or more, in their own vehicles, while horse delivery was limited to the city. stables, always a nuisance and a breeding place of disease, have been practically eliminated from cities, and street-cleaning has been rendered much easier. real estate remote from rail ways has in many instances considerably appreciated in value as a result of the advent of the motor-car, rendering it accessible to the city man. in the foregoing the utilitarian aspect of the motor-car has been specially emphasised. while cars are still being built that can properly be classed as vehicles of sport and luxury, they form a small proportion of the whole production. in new york city an annual show was established for this class of car; it started as the importers’ salon, but during the world war, when the im- portation of european cars was very difficult, it gradually changed its character and became a show of high-grade domestic as well as imported cars. at the salon in nov. 1920, there were exhibited cars selling at upward of $20,000, whereas a serviceable five- passenger car could be bought for as low a price as $550. the luxury cars exhibited at these shows were characterised by high power and high speed, elegant body finish, fine upholstery and superior equipment. european conditions.—in 1910, great britain had the leader- ship among european countries as regards the number of cars in use, whereas trance led in respect to volume of production. about one-half of the number of cars produced in france at that time were exported. in continental europe the introduc- tion of motor-cars was hampered by heavy taxation on the cars themselves and on the fuel. the use of motor-trucks, on the other hand, was encouraged by the so-called subsidy system, by which purchasers of trucks suitable for military purposes were offered by their governments a bonus on the purchase price and also on the upkeep cost, in consideration of their keeping the trucks always in fit condition and agreeing to turn them over to the govt. in case of war. great britain, france and germany had such subsidy systems before the war; japan adopted. the same policy later. as soon as war was declared the motor-car factories were set to work for the war departments, either making trucks or other vchicles for the transport corps or else manu- facturing aero-engines or munitions. soon all the petrol avail- able was needed in war service, and the use of motor vehicles by private parties practically ceased. in england some use was made during the war period of town gas for motor fuel; this was carried in a collapsible bag of rub- berised fabric, on the roof of single-deck omnibuses, for instance. with this fuel it was possible to obtain about 85° as much power from an engine as with petrol, and a satisfactory mileage on one filling was secured. under normal conditions the gas would have motor vehicles puate i. fic. t. austin (british) light car. fic. 2. citroen (french) open car. fic. 3. mercedes (german) racer. fic. 4. ford (american) touring car. fic. 5. buick (american) roadster. itc. 6. cadillac (american) 7-passenger car. fig. 7. napier (british) limousine. fic. 8. rolls-royce (british) salamanca cabriolet. plate it. motor vehic les { me wee mm a ns! *. oe ~~ ts} > r j tcoap not 10 (etme me fic. 1. six-wheel luxury type coach. fic. 2. benz (german) 5-ton truck chassis with diesel engine. fic. 3. crossley (british) subsidy type 3500 lb. truck with war dept. type body. motor vehicles been carried in steel bottles under high pressure, but owing to military requirements no steel could be spared for this purpose. the central powers suffered much more from fuel shortage than did the allies, and extensive researches on substitute motor fuels were carried out in germany. after their petrol supply ran low the germans used benzol, petroleum mixtures, benzol-alcohol mixtures, alcohol, wood alcohol, tar oil, gas oil and shale oil, as well as fuels produced synthetically from water gas by catalyt- ic hydrogenation under high pressure and at high temperature. registration in great britaitn.—according to an announcement by the minister of transport, great britain, on march 31 1920, had 185,700 private passenger vehicles and 71,400 public-service vehicles. the numbers of lorries and motor-cycles in service on that date are not available, but during the period jan. 1—march 31 1921, licences were issued for 15,000 motor lorries and 278,500 motor cycles. hlow rapidly the use of the motor vehicle increased during the next four years may be judged from the following figures issued by the same authority as on may 31 1925: licences issued for private passenger cars, 532,909; for motor cycles, 518,457; for commercial goods ve- hicles, 216,966; for hackneys, 92,024; trade vehicles, 13,018, and official vehicles, 14,912. registration in the united states—the figures given in table i. are based on information furnished to awtomotive industries by the registration officials of the different states. allowances ofd more than tenfold and that during the following four- and five-year periods, although the proportional rate of increase was less, the absolute increase was far greater. province 1910 1915 i9ig 1924 ontario ; 4.200 | 42,346 | 144,804 | 306,770 saskatchewan. ; 531 10,225 | 56,855 | 69,895 quebce : . . , 786 i1o,1i2 | 33,547 | 82,982 alberta : ; : : 42 5,832 | 34,000 | 48,255 manitoba . ; 1,522 22 30,118 | 44,015 british columbia — . . 1,026 8.360 | 22,420 | 52,325 nova scotia 148 1,841 10,290 | 20,610 new brunswick 299 1,900 8,306 | 19,794 prince edward i... ; 35 790 2577 yukon ; : : ne 69 89 ie totals 8,937__| 89.945 | 341,219 | 647,223 i table it. registration of passenger cars, lorries and motor cycles tn different countries at the end of 19024 ({n round number) | passenger 1924 1918 i9i2 alabama 157,262 46,155 3,385 arizona 57,828 23,875 1,62. arkansas . 141,983 41,458 2,250 california 1,321,480 337,878 88,699 colorado . 213,247 80,000 8,950 connecticut 214,318 84,902 24,101 delaware . f ‘ 35,136 12,955 1732 district of columbia 91,726 47,514 1,722 florida 194,196 47,059 1,749 georgia 209,300 99,160 19,120 idaho 69,225 342,282 2,500 illinois 1,123,724 389.135 68,073 indiana 650,219 227,160 54,334 iowa . 620,906 327,500 47,188 kansas 410,891 189,952 22,000 kentucky 231,784 65,884 5,147 louisiana . 178,000 39,760 7,000 maine - 127,178 44,572 7743 maryland 195,581 78,146 10,487 massachusetts 672,315 193,497 50,132 michigan . 868,587 261,547 39,579 minnesota 502,987 203,727 29,000 nlississipp1 134,547 40,000 2,895 missouri 544,635 187,646 24,379 montana . 79,695 51,050 2,000 nebraska . 308,713 175,370 33,861 nevada 18,387 8,160 9g00 new hampshire 71,929 24,904 5,764 new jersey 504,190 154.870 43,056 new \nlexico 41,750 16,893 oii new york : 1,412,879 457,924 107,262 north carolina 305,756 72,300 6,178 north dakota 117,061 71,687 8,997 ohio . 1,244,000 417,400 63,066 oklahoma 342,982 120,300 6,524 oregon 192,629 66,607 10,165 pennsylvania 1,228,586 393,972 59,357 rhode island 90,652 30,595 8,565 south carolina 163,382 55,400 10,000 south dakota . 142,280 86,121 14,481 tennessee 204,680 65,000 9,973 texas 834,040 250,201 35,187 utah . 79,233 27, 204 2,576 vermont 61,179 22,550 4,283 virginia. 261,643 72,228 5,760 | washington 294,812 119,905 13,990 west virginia . 190,134 38,600 5.349 wisconsin 525,221 196,544 24,578 | wyoming . 43,639 16,150 1,300 | totals 17,726,507 | 5,113,999 1,007,882 | table i. u.s. registraitons were made for re-registration of cars sold by their owners during the registration year and for registration of cars by non-residents, and the table is believed to give as accurately as possible the number of cars in service in each state during the years mentioned, by residents of the respective states. registration in canada.—the following table shows that during the period ig10-5 the number of cars registered in canada increased | motor- | : oie lorries cycles total a ae [afar eee es united states ; 15,597,000 2,142,000 | 139,000 |{ 17,878,000 great britain 625,000 | 217,000 | 518,000 1,360,000 france 460,000 | 115,000 | 102,000 677,000 | canada 576,000 63,000 8,000 647,000 germany 132,000 61,000 98,000 291,000 australia 180,000 18,000 55,000 253,000 italy 72,000 28,000 38,000 138,000 argentina . 120,000 5.000 3,000 128,000 spain . 56,000 10,000 7,000 73,000 holland 24,000! 36,000 60,000 norway 13,000 5.000 7,000 | 25,000 | 1 includes both passenger cars and lorries. il. technical developments a most desirable feature in a motor car js flexibility, that is, the ability to pass from a low to a high speed by merely opening the throttle valve. this is secured by using an engine of great power in proportion to the combined weight of the car and load. american cars have been specially noted for their flexi- bility, due to the use of very large engines, notwithstanding the fact that the high fuel consumption per mile travelled tends to increase with the displacement of the engine. as motor fuel was much more expensive in europe, european designers could not ignore the factor of fuel economy as american engineer’ could. engine design.—tn engine design the constant endeavour is to get greater output from an engine of given piston displace- ment. iflorsepower output depends upon two factors, the mean effective pressure upon the piston head and the linear speed of the piston. it was not possible to increase greatly the mean effec- tive pressure; in fact, changes in the character of the fuel used for motor cars, by which some very much less volatile fractions were included than in motor fuel of the earlier period, made it necessary to operate with lower compression, which resulted in a lower mean effective pressure. however, improvements in com- bustion chamber design and other changes more than balanced this loss. a great gain was made by increasing the speed of operation. in 1905 the average engine speed corresponding to maximum engine output was about 1,000 ft. per min.; in 1926 it was approximately 2,500 ft. per min. for passenger-car engines and over 4,000 ft. per min. for racing engines. the first step to increase engine speed was enlargement of valve ports and pas- sages, enabling the engine to draw in a normal amount of charge at a higher speed. the valve timing was also changed, the ex- haust valve being given a greater lead and the inlet valve a greater lag. next, the reciprocating parts (piston and connecting-rod) were lightened, so as to reduce the inertia forces on them and the bearing pressures resulting therefrom. this led eventually to the adoption of aluminium alloy pistons. aluminium has a higher co-efficient of heat expansion than cast iron, so that the aluminium piston must be given a greater clearance in the cylin- der, which tends to result in unpleasant piston slap when the 974 engine is cold, and also in “ oil pumping,” that is, transfer of lubricating oil from the crank chamber to the combustion cham- ber, with consequent smokiness of the exhaust. these difficulties were overcome in later designs by the use of the split-skirt or constant clearance type of piston, in which the skirt or lower part is separated from the upper part or ring belt all around and is saw-slotted longitudinally so that when the aluminium ex- pands the saw-slot will become narrower and the clearance be- tween piston and cylinder wall remain substantially the same. in a few instances magnesium alloy pistons and heat-treated duralumin connecting rods were used, magnesium having a specific gravity about two-thirds that of aluminium, and duralu- min, an aluminium alloy responsive to heat treatment, having the strength of mild steel with only one-third its specific gravity. special means were resorted to in attempts to build ultra high- speed engines, as for racing and similar purposes. ‘these included the use of two inlet and two exhaust valves per cylinder, the use of two simultaneous ignition sparks in each cylinder, and the use of crankshafts in which each individual throw was counter- balanced. cylinder development.—by increasing the number of cylinders above the one or two employed in the first machines, engines can be reduced in weight, and the objectionable vibration can be minimised. in 1926 the four-cylinder engine was the foremost type for use on vehicles of a strictly utilitarian character; the six-cylinder was the luxury type in europe, while in the united states it was the preferred type for passenger cars of intermediate and higher grades. most of the more expensive passenger cars in the united states then were fitted with eight-cylinder engines. the twelve-cylinder or twin-six engine enjoyed a spell of popu- larity during and immediately after the war but disappeared from the market as a motor-car power plant in 1923. in a petrol engine the torque impressed upon the crankshaft is always non- uniform, no matter how many cylinders there are, but the tluc- tuations decrease with an increase in the number of cylinders. in a four-cylinder engine there is, as with one or two cylinders, a reversal of the torque; that is, just before the end of each stroke the flywheel not only supplies all the power delivered by the engine, but also some of the power necessary for keeping the crankshaft and pistons in motion. six cylinders are the smallest number delivering continuous torque at the crankshaft; but while continuous, the torque is still far from being uniform; with eight cylinders the torque fluctuations are reduced, and with twelve they are still smaller. arrangement of cylinders—four and _ six-cylinder engines were always arranged vertically, with all cylinders in a row; eight-cylinder engines were originally built in v form, but in 1926 the majority of the makes had all eight cylinders in line. in an eight-cylinder v engine with the two cylinder blocks at an angle of go°, and with a single plane crankshaft there is an unbal- anced periodic inertia force in the horizontal plane, the period of which is equal to the time of one-half a crankshaft revolution. by placing the two cylinder blocks at an angle of 60° a uniformly rotating unbalanced inertia force of constant value is obtained, of a magnitude considerably less than the maximum value of the unbalanced force in the go” v, and this led two makers, lincoln and wills, to use this arrangement of the cylinders, which, in- cidentally, suffers from the disadvantage that the explosions are not evenly spaced but come at 60° and 120° intervals. a methed of completely balancing an eight-cylinder 90° v engine was discovered by prof. archibald sharp and described in his book on the balancing of engines, issued in 1907. it was first practically adopted by the cadillac motor co. in 1923. instead of having all four throws of the crankshaft in a single plane, the throws are arranged in two planes making an angle of go° with each other, and the crankshaft is provided with two heavy balance weights, as shown in fig. 1, which represents the cadil- lac crankshaft. in deciding upon the form of the crankshaft of a multi-cylinder engine and the angle between cylinders in a v engine two objects are aimed at, namely, to ensure uniform spac- ing of explosions and inherent balance of reciprocating parts. both objects can be attained in six and eight-cylinder engines; ¢e motor vehicles in a four-cylinder vertical engine there is an unbalanced recip- rocating force in a vertical plane, causing vibration of the engine. this can be overcome only by the use of an anti-vibrator, in- vented by if’. w. lanchester, consisting of an unbalanced mass directly below the crankshaft and driven from the latter at twice its speed. fig;. t taltict craittthatt for 90° v-type eight-cylinder engine (cadillac). when multi-cylinder engines were first used the cylinders were generally either cast separately or in pairs; later it became the practice to cast all cylinders in one row in one block. this greatly simplified the outward form of the engine, as with such a cylinder block only one pipe connection each need be made for the cooling-water inlet, the cooling-water outlet, the combusti- ble charge from the carburetter and the exhaust. some manu- facturers even cast the top part of the crankcase integral with the cylinder block and made the lower part a steel pressing. this construction lent itself well to quantity production. most makers of the higher-priced cars, produced in smaller numbers, cast all parts of the crankcase of aluminium. cylinder heads were generally cast separate from the cylinder block and fitted to the block with a gasket of sheet copper and asbestos between. this construction facilitated manufacturing operations, and when the engine was in service permitted decarbonising the com- bustion chamber by scraping without removing the cylinder. it also made it possible to machine completely the combustion chambers, and thus to get all the chambers in one engine of exactly equal volume. combustion problems.—as the speed of automobile engines increased it became necessary that the combustion of the fuel mixture charge be completed in a shorter period of time, in order that the maximum fraction of the heat energy might. be con- verted into mechanical work. racing engines in 1925 operated at speeds above 5,000 r.p.m., at which the time of one complete piston stroke is less than ;45 sec., and combustion should be completed before the end of the stroke. prof. bertram hopkin- son observed in 1912 that the rate of flame propagation through a combustible mixture can be increased by producing were in the mixture (in the experiment, by means of a revolving fan in a closed vessel containing the mixture). in order to obtain a similar effect in the com- bustion chamber of an engine, harry ricardo has suggested the use of a “‘ tur- bulence cylinder head,” as illustrated in fig. 2. the compression space is in the form of a pocket in the cylinder head, mainly over the valves, which are lo- cated ina side pocket, but partly over the cylinder itself. at the end of the com- pression stroke the piston approaches very close to the flat portion of the cylinder head, and this produces a lateral rush of the combustible gases into the compression pocket, causing turbulence. compression heads of this general form were widely used in 1926. the compression space should be as compact as possible, so that for a given volume its surface area and the distance from the spark points to the remotest portion of the charge are both a minimum, as this tends to promote rapid combustion, to pre- vent detonation (excessive explosion pressure and resulting phe- nomena) and to reduce the loss of heat energy to the cylinder jacket. recognition of these relationships led to the gradual abandonment of the t head type of cylinder (with inlet and exhaust valves in pockets at opposite sides) and to the wider fic. 2 larbuldtee type cylinder head. motor vehicles adoption of the valve-in-head engine, which latter in 1926 was used on racing cars to the exclusion of all other types. valves in the cylinder head can be operated either from a camshaft in the crankcase through tappet rods extending up the side of the cyl- inder and tappet levers on top, or from an overhead camshaft. the overhead camshaft design reduces the weight of the valve reciprocating parts, and with given valve spring pressure makes possible the use of higher engine speeds. racing and air-crait engines (see aero-engines) were generally fitted with overhead camshafts. on the other hand, in passenger car engines valves in the cylinder head were generally operated through long tappet rods, as it was found difficult to obtain the desired degree of silence with overhead camshafts. | marmon, in the united states, used a cast aluminium cylinder block for a passenger car engine for a number of years prior to 1920, but gave it up because it proved impossible to keep the cylinder bores true. cast-iron sleeves were inserted in the blocks to form bearing surfaces for the pistons, and the valves were located in cast-iron cylinder heads. the trouble was evidently due to distortion of the aluminium castings under the high tem- perature of operation. it was later found that distortion of alu- minium engine castings in service can be prevented by subjecting them to a heat treatment after machining, at a temperature slightly higher than the maximum they reach in service. some years after the war, german engineers became interested in aluminium engines, and at the berlin automobile show of 1923 there were exhibited six makes of car with such engines. fuels.—the continual lowering of the volatility of the fuel used caused both manufacturers and users of motor cars a great deal of trouble, particularly between ro915 and 1920. when motor cars were first used, the fuel sold consisted of a compara- tively narrow range of highly volatile hydro-carbons. when sprayed into air at atmospheric temperature in the required pro- portion of about one part by weight of petrol to 15 parts of air it vaporised readily. the fuel supplied in the united states in 1920 had an end point of nearly 475° f., that is, the least volatile constituents, when under atmospheric pressure, boiled only at that temperature. hence, in order to vaporise this fuel com- pletely it was necessary to supply heat to the mixture or to the components before they were mixed. when trouble from incom- plete vaporisation was first experienced the carburetters were provided with a jacket through which hot water from the engine jacket was circulated. when this no longer sufficed, the air for the carburetter was drawn through a muff surrounding a part of the exhaust manifold, and to prevent recondensation after the mixture was formed, the inlet manifold was so arranged that it was completely surrounded by hot water. this also proved inadequate, and then the hot spot or exhaust- heated manifold was introduced. when the fuel is incompletely vaporised the liquid particles tend to separate out of the mixture at the bends in the manifold, and it is very difficult to insure that all cylinders get mixture of the same composition. those portions of the manifold wall where the liquid particles tend to accumulate are then made to form parts of the exhaust manifold wall also, so that they are constantly kept at a high temperature, and the liquid particles upon striking them flash into vapour. the change in the character of motor fuel between 1916 and torg is strikingly illustrated by the diagram (fig. 3) of distillation curves of the fucls purchased in detroit, mich., at various times during that period. later the fuel improved again slightly and a survey made by the u.s. bureau of mines on jan. 1 1925, showed an average end point for petrols sold in different parts of the country of 425° fahrenhcit. carburetters—numerous improvements in carburetter design were made between roro and 1926. decreased volatility of the fuel necessitated the provision of special means to facilitate en- gine starting, particularly in cold weather. american engineers, who were confronted with the problem first, generally made use of a choke valve in the air inlet, which is closed when it is desired to start. this greatly increases the suction on the fuel nozzle and results in a great excess of fuel being drawn in. as only the most volatile part of this fuel will be vaporised, this excess of fuel 500 bec a we 450 « prp, i s pall & d n 5 400 = + 4 es if aa ee i= ia ‘soin 3 any 3 = hh af als e ban 748! t+ 4 2 eo | ee ca t ly ae 300 on za la aan 1 a : a tt e eee ge cer ae pig ptt ee aa ate al 250 pete 14-3 i 44 bae e a | ang08 g e aa a 200 fi bee 2 | sake ls | - rt {| 8 der s a a pt 150¢f zzanee as — ttt ar) | et 4 a im epefele ly eae pt] toot as | | [ ao; [ [ef [ [0 fic, 3.—distillation curves of motor fuel sold in detroit, mich., from 1916 to 1919. the data for each curve are as follows:— curve no. fuel date of purchase baume i petrol 4/5/16 60-5 2 petrol 7/10/16 57°5 3 petrol 9/11/16 56-8 4 petrol 6/9/17 56:8 5 petrol 1/24/19 57°3 6 petrol 4/30/19 55°7 7 petrol 6/18/19 55:0 g alcohol 10/18 12-2 9 cal. dist. 18 51-4 10 paraffin 18 40:0 assures the formation of an ignitable mixture. another scheme, which originated in europe, consists in the provision of a special starting nozzle delivering fuel into the carburetter passage above the throttle valve. for starting, the throttle is closed and the effect on the start- ing nozzle is then the same as that on the main nozzle when the choke valve is closed. most of the earlier carburetters had the fault of delivering an impoverished mixture in case the throttle valve was opened suddenly, causing the engine to halt and even to stop. with later carburetters the fuel-metering orifice is placed at the bottom of the carburetter instead of at the top of the spray nozzle. between it and the top of the nozzle an accel- erating well is provided which filled with fuel when the engine was stopped or throttled down to a low speed. then, if the throttle were opened suddenly, the contents of the well were discharged into the induction system almost instantly, and the richness of the mixture was maintained. another improvement that came into wide use on carburet- ters between 1920 and 1926 was the economiscr. research work on carburetters and engines showed that for best all-round re- sults the strength of the mixture must be varied with the demand on the carburetter. maximum power js obtained from the engine with a petrol-air mixture of about 1:12-5, whereas the maximum fuel economy is obtained with a mixture of about 1:16. at extremely low speeds the mixture should be comparatively rich, because the fuel then is not sprayed very energetically and not all of it is vaporised, and only the vaporised fuel counts in the mixture. throughout the greater part of the range in demand the carburetter should furnish the maximum-economy mixture, for obvious reasons. however, if the throttle is opened wide, the driver wants either the maximum torque (as in ascending very steep hills), or else the maximum power (as in a burst of speed), and in that case the carburetter should deliver the maximum- power mixture. this is accomplished by making the stem of the throttle valve, when approaching the position of maximum opening, change the setting of the fuel metering devices in such a way as to enrich the mixture. azy cleaners —about 1920, american manufacturers began to use air cleaners on passenger car engines, to prevent road dust from getting into the cylinders and causing abnormal wear. the cleaners used were of either the centrifugal or the strainer 976 type. with the former the air is set in rotation in a cylindrical chamber by being drawn in by the engine suction through tan- gential or helical passages. centrifugal force caused the heavy dust particles to collect on the cylinder wall and to drop out into a collector, often a glass jar, while the air, deprived of its dust content, is drawn off at the centre of the cylinder. with the strainer type the air is drawn through a large area of filtering felt. ° one difficulty encountered in the use of exhaust heat for vapor- ising the fuel is that the heat supplied does not vary in accordance with the needs when the load on the engine is varied. when the engine is heavily throttled and runs under light load at low speed, the suction on the spray nozzle is small, and consequently the fuel is not finely spraved. relatively more heat is needed to ensure the vaporisation of the larger globules of fuel, but under these conditions of operation the exhaust does not supply a great amount of heat. a device designed to overcome this diffi- culty was developed by the packard motor car co,, and is known as the fucliser. with this (see fig. 4) a variable fraction spark plug ni aio heating jacket ey) fic. 4.—cross section of packard fueliser. of the mixture prepared in the carburetter mixing-chamber is shunted around the throttle valve and through a heating jacket of the carburetter, where it is kept burning by a constant stream of sparks delivered by a sparking plug. the products of combus- tion are combined with the main stream of combustible charge and pass on into the cylinder. when the throttle valve 1s fully open there is very little resistance to the passage of the combustible mixture past it, and very little then flows through the by-pass or heating jacket; on the other hand when the throttle is nearly closed the passage through it offers much more resistance, and a much greater proportion of the fuel charge passes through the heating jacket, which is in accordance with the requirements. feed systems.—in early cars the fuel tank was almost invaria- bly located in the front seat, and the fuel was fed by gravity to the carburetter. later the bodies were constantly lowered, partly to secure greater stability and partly for the sake of appearance, and at the same time the carburetter had to be raised in relation to the engine, owing to the lessened volatility of the fuel. the result was that sometimes when the car had to ascend a steep grade and there was little fuel in the tank there was no hea on the fuel, and none would fiow to the carburetter. some of the earlier high-class cars were provided with a pressure fuel feed system, by which gas under pressure, taken through an “ adap- we motor vehicles ter’ from the engine cylinders, was made use of to force petrol from a tank carried on the frame at the rear to the carburetter. there were two major objections to this system of feed: carbon particles from the engine cylinder often got intc the fuel tank (in spite of the gas being passed through a fine-mesh wire-gauze strainer) and thence into the carburetter jet, which sometimes became clogged; besides, every time the fuel tank was filled the compressed gas escaped, and to get an initial flow it was neces- sary to obtain pressure by a hand air-pump. by placing the fuel tank under the cowl instead of in the front seat, sulhcient head for gravity feed was generally obtainable, but the cowl tank usually had an awkward shape and was of rather smal) capacity. the solution was found in the vacuum feed system, developed by the stewart-warner speedometer corp., chicago, by which (fig. 5) the suction or vacuum in the inlet pipe of the engine was used for transferring the fuel from a rear tank to an auxiliary tank mounted on the forward side of the dashboard, as high as possible. the auxiliary tank had two compartments, upper and lower. into the upper com- partment the fuel was drawn by the vacuum, and it was peri- odically transferred to the lower by a float valve. thence it flowed to the carburetter by gravity. there was always sufficent fuel in thecarburetter float chamber and in the auxil- iary tank to start the engine after the main tank had been refilled. ignition.—in 1910 ignition on practically all motor-cars was by high-tension magneto. in 1926 al! american passenger cars, with the exception of the ford (which had a flywheel type of magneto of the maker’s own manufacture), had battery ignition. in european coun- 4 , 3 tries, on the other hand, al- { aril: though a beginning was made . ! wi with the replacement of the magneto with the battery and coil system, upon the adoption of electric starting and light- ing the movement was soon checked, and in 1925 only 16 out of 133 british models had battery ignition, while in france battery ignition was even less popular and in germany it was practically non-existent. what led american engineers to change from magneto. to battery ignition on passenger cars was the adoption of electric lighting and starting during the period 1912-4. any car so equipped had an electric generator and a storage battery; consequently there was a constant and plentiful supply of current available, ancl there was no need for an additional current generator in the form of a magneto. as compared with the early coil and battery systems, the only diflerences consisted in the use of a plain coil instead of a vibrator coil and of a mechanical interrupter instead of a timer. sometimes safety devices were provided for auto- matically opening the circuit or reducing the current flow if the operator should forget to open the switch when the motor stalled. use of thermostats—no fundamental changes were made in the cooling system, with the exception of the introduction of the thermostat for the control of the circulation. this instru- ment is connected in the cooling circuit in such a manner that it prevents circulation through the radiator until the jacket water has attained a certain predetermined temperature, generally a ij ‘ pened ee from oltt, main gasoline jam tank to carbureter fic. 5.—cut-away view of stewart vacuum tank (fuel feed system), motor vehicles about 170° fahrenheit. the result is that in starting from cold the engine reaches normal working temperature in shorter time, and trouble due to incomplete vaporisation of fuel is reduced. the thermostat used, known as the sylphon, consists of a corru- gated copper cylinder filled with a liquid which vaporises at the temperature at which the thermostat is to act (fig. 6). an al- py flap: qe to radiator wy ltt: fic. 6.—thermostatic valve for control of engine temperature. ternate system consisted in the provision of a set of radiator shutters, thermostatically controlled. many passenger car radia- tors are fitted with a radiator thermometer in the filler cap, which is a help to the operator in trying to keep his engine running at its best temperature and gives ‘an early indication of incipient overheating. lubrication.—as regards engine lubrication two basic methods came into use, the circulating-splash and the force-feed or ‘< drilled crankshaft ”’ system, as well as combinations of the two. both systems were employed on early cars, but the force-feed system came into much more extensive use with the development of the high-speed engine. the problem of engine lubrication was rendered much more difficult by the change in the character of the fuel used. a good deal of the fuel entered the cylinder in the unvaporised state, and some of it leaked past the pistons into the crankcase, where it diluted the lubricating oil. in 1920 it was a common experience to find a fresh supply of lubricating oil lose much of its viscosity, and hence of its lubricating value, during the first 100 m. of running. heating of the crankcase oil also reduces its viscosity, and to reduce this heating many brit- ish engines were cast with cooling flanges on the bottom of the oil sump. starting and lighting gear.—one of the greatest advances in motor car practice was the development of electric starting and lighting systems. the first such system on a car in regular production was on the cadillac in 1912, and was the design of c. f. kettering. electric lighting alone had been used on pet- rol cars for some years previously, in fact ever since the advent of the tungsten filament bulb. at first the lamps were supplied with current from a storage battery only, which had to be re- charged periodically from electric mains; later they were fed with current from a generator and storage-battery installation. the adaption of an electric generator to storage-battery charg- 977 ing on a motor car presented considerable difficulties, for the reason that the petrol motor runs at widely varying speeds, and that the voltage of the generator, therefore, tends to vary within wide limits, whereas a substantially constant voltage is needed for charging. many systems of regulation were used with more or less success, but finally the so-called third-brush system was adopted by a majority of the manufacturers of electrical equipment. in this system the generator field was provided with a winding similar to a shunt field winding, but instead of connecting the positive commutator and negative brushes it was connected be- tween one of these brushes and an auxiliary brush, so that only a fraction of the voltage generated in the armature was applied to the field coils. this system of control did not give a constant generator voltage, but with a storage battery connected to the generator it kept both the voltage and the charging current within permissible limits of variation. in connection with the electric starter the main problem was that of the drive to the engine crankshaft. after trying various devices nearly all manufacturers in the united states and a good many in europe settled upon the use of the bendix drive (fig. 7), developed by vincent bendix of chicago. onanextension cushion spring starter pinion inestia weight fic. 7.—bendix drive for electric starters. of the starter armature shaft was loosely mounted a sleeve, which was placed in driving connection with the shaft through a coiled spring. the spring had a coarse, square thread cut on its outside, and on this was mounted the driving pinion, the hub of which was cut with a corresponding female thread. when current was applied to the starting motor, which was always of the series wound type, the armature started to revolve at great speed, carrying along the threaded sleeve on its shaft. owing to its inertia the pinion lagged behind, and was screwed along the shaft and thus shifted into mesh with a gear-ring on the flywheel rim. upon abutting against a collar it became fast upon the sleeve, and the starter then cranked the engine, the shock being relieved by the coiled spring. as soon as the engine began to pick up its cycle the flywheel ran ahead of the driving pinion, and the latter was automatically thrown out of mesh by being forced along the screw. fig. 8, generator starter fic. 8.—fiat (italian) engine, showing method of mounting electric generator and starter, 978 illustrating the fiat motor car engine, shows one method of mounting the generator and starter. a necessary part of prac- tically all motor car electric equipments was a battery cut-out, which automatically disconnected the battery from the generator when the engine speed dropped so low that the generator vol- tage was less than the battery voltage, and connected it on in- creasing engine speed when the generator voltage surpassed the battery voltage. ground return wiring was very much used, all electric appliances having one insulated and one grounded con- nection. the standard voltage for motor car electric systems in the united states was 6 v., while in europe a pressure of 12 v. was much used. superchargers or means for forcing into the cylinders a greater mass of charge per cycle than they can draw in by their pumping action received a good deal of attention during the latter part of the war as a means of maintaining the power of aircraft engines at high altitudes. in 1926 the supercharger was commonly used on racing engines and permitted of greatly increased output from an engine of given displacement. on one make of stock car, the mercedes, the supercharger was fitted as standard equipment. an air-pump of the roots blower type was mounted at the forward end of the engine and driven from the crankshaft through a friction clutch, which latter was controlled by the accelerator pedal. as long as the throttle was not fully opened the clutch was disengaged and the supercharger therefore idle. a further movement of the pedal after the full-open position of the throttle had been reached, closed the clutch, set the supercharger in action and gave an increase in maximum power of about 65%. gears.—unit-power-plant construction, that is, the combina- tion of the engine, clutch and change-speed gear in a single unit, became very popular, and in the united states was the almost universal practice for passenger cars. about 1g1o the dry-disk type of clutch (fig. 9) began to displace the multiple disk-in-oil and the, cone type. it was very similar to the lubricated type of disk clutch in construction, but one set of the metal disks was faced with disks of asbestos fabric on both sides. its advantage over the lubricated disk clutch was that its operation was not afiected by changes in atmospheric temperature, as was that of the latter. most of the earlicr dry-disk clutches were of the multiple-disk form, but from 1920 on the single-disk type gained constantly in popularity and in 1926 was used with engines of as much as 70 horsepower. ‘this differs from the multiple-disk form not only in having only a single driven disk, but also in having a set of reducing levers which make the thrust on the throw-out collar about one-quarter the pressure between the disks, whereas in the multiple-dry-disk design illustrated in \\ flywheel rim clutch drum clutch springs throw-out spigot be aring fic, 9.—sectional view of dry-disk clutth. motor vehicles fig. 9 the two forces are equal. there were no important de- velopments in the design of gearsets or transmissions; nearly all manufacturers of passenger cars used the selective sliding pinion type, and this type was also used on most commercial vehicles. chain drive was almost entirely discarded, except on trucks in continental europe, and shaft and bevel-gear drive became the standard for passenger motor cars throughout the world. but two important improvements were made in this drive. one was the substitution of spiral bevel for straight bevel gears, to secure quiet operation, and the other the partial substitution of disk universal joints for the metallic type, the former requir- ing no lubrication. the spiral bevel gear (fig. 10) was made pos- fic. 10.—central part of a rear axle with inspection cover removed, showing spiral bevel gear. sible by a gear-cutting machine developed by the gleason works of rochester, n.y., and the fabric disk universal joint (fig. 11) by a fabric structure originated by ed. j. mardy & co. of coventry, england. practice in regard to final drives for motor lorries remained in a chaotic state in 1920. in continental europe the chain was still predominant, while in great britain and the united states the worm drive was in most extensive use. of the lorry models manufactured in great britain in 1926 50% had worm drive, 5° chain drive, 12% bevel gear drive, 1% internal gear drive, and 25% the double- reduction drive, or drive by one pair of bevel and one pair of spur gears enclosed at the middle of the axle. in the united states the most popular drive next to the worm, for trucks of over 1} ions capacity, was the internal gear drive, in which there was a first reduction by bevel gears at the middle of the axle and a second by internal gears at the driving wheels. axles and springs.—in connection with lorry axles, mention should be made of the development and use, mainly in the united states, of so-called non-stalling differential gears. a vehicle fitted with this type of differential would not lose all traction when one driving wheel gets on slippery ground; on the other hand, in turning corners the drive was entirely through the inner sheet: a type of body suspension spring that gained much in popularity between roto and 1920 was the cantilever type first used by f. w. lanchester in england. the most extensively used type in 1926 was the half-elliptic. many attempts were made to solve the problem of furnishing the springs with effec- tive means of lubrication, to make them as supple as possible and to prevent squeaking, and in england the practice of enclos- ing the springs in leather gaiters gained some ground. in the connection between the rear axle and the frame, provision must be made for taking up the driving thrust necessary to overcome the air resistance and the resistance encountered by the front wheels, as well as the reaction to the rear-wheel driving torque, which tends to turn the axle housing in the direction opposite 11.-—thermoid-hardy fabric universal joint. fig. motor vehicles to that in which the wheels are turning. in the hotchkiss drive, both the drive and the torque reaction were taken up on the body springs, which were securely clipped to the axle housing and di- rectly pinned to the frame at their forward end. this pattern became very popular in the united states for both passenger cars and lorries, and was successfully used even on heavy military lorries. european designers, on the other hand, favoured the torque- tube construction for passenger cars. in this the propeller shaft was surrounded by a torque tube, which was rigidly secured to the housing at the centre of the rear axle, and at its forward end had either a forked or a spherical connection to a cross member of the frame or the rear end of the transmission case. in the united states one manufacturer after another adopted the plan of mounting the steering post on the left side, realising that in a country where the “ right-hand ” rule of the road obtains, the balance of advantages rests with the left-hand drive. left-hand steering fits in well with brake and gear-shift levers mounted in the centre of the car, as the driver can use his right hand to operate them. in great britain, where the rule of the road is to ‘‘ keep to the left,” right-hand steering has the same advan- tages as left-hand steering in other countries. wheels.—the wheel equipment of the earlier cars was almost entirely of wood-spoked type. woods suitable for rims and felloes became rare, however, especially in europe, and a strong tendency toward the use of metal wheels then set in. in fact, with one exception, all british manufacturers of passenger cars fitted metal wheels as regular equipment on their 1925 models. there were three types of metal wheels for passenger cars, viz.: wheels similar in shape to wood-spoked wheels, made of two steel pressings welded together (chiefly used in england), wire- spoked wheels and disk wheels (figs. 12, 13 and 14). an improvement in wire-wheel design, which was a great factorin rendering these wheels practical for heavy, powerful vehi- cles, was the triple lacing due to john v. pugh of england. disk wheels came into extensive use during the war; they may be divided into single and double disk types. to secure the necessary lateral stiffness with a single disk it was customary to cone the disk, and, moreover, the disk was usually re- duced in thickness from the hub toward the rim, cither by turning in the lathe or by rolling. all motor-vehicle wheels are pro- vided with steel rims designed to take the pneumatic or solid rubber tires (see trres). the original type of motor-vehicle rim for the dou- ble-tube pneumatic tire was the clincher rim, the edges of which are formed into clinchers to hold the beaded edges of the tire cover. this type of rim remained the standard in europe, but ameri- can manufacturers early adopted the detachable rim, which per- mits of the use of a steel cable core in the edges of the tire cover to make it inextensible. in the earlier detachable rims one flange of the rim was removable, and the tire could be stripped off sideways after the flange had becn detached. some of these detachable flange rims could be used with both clincher and straight-sided tires, and were therefore known as universal rims. later, when the clincher tire was given up by american manu- facturers for all except the smallest sizes, a different type of detachable rim was introduced, in which there is a joint in the circumference of the rim. after opening the locking mechanism of this joint the rim can be contracted sufficiently to pass through the tire. in order that detachable rims may always be free- fic. 12,—section of rudge- whitworth demountable wire wheel with pugh triple lacing. 979 working the rims must be thoroughly rust-proofed, and care must be taken in handling the rim not to distort it. tire repairs —in the early years of the motor-car, when a tire was punctured or otherwise defective, the operator was -< ~ ie yy e fic. 13.—michelin disk wheel, outside view and section. obliged to make a repair on the spot, or at least remove the tire cover, insert a new tube, replace the cover and inflate the tire anew. the difficulty was overcome by the adoption of the de- mountable wheel in europe and the demountable rim in america. amcrican motorists thereafter carried one or two spare rims fitted with fully inflated tires, and in case of a puncture merely removed we ~ @ ) et oe wr) na cela wat wrt ae par) a a ¥) 4 ‘ i ‘ } 4 e clit ae tea % oa. a —— ces ea @ 1» oo @ pot “ mt [7 rw e 9 &, ' ne wd, a . e° . pi et aeeee ie tun ; * reh . } ee we 9 easrenleematendieegreire nannerl an wsr wel hw) 2000oe e€ %@ pf ek rer ante ee ono ¢ wad 9. | af 3 ty 6 sf de hd fic. 14.—sankey pressed steel wheel, and section. the rim with the defective tire and replaced it with a spare rim and inflated tire, an operation usually requiring from ro to 15 min- utes, leaving the repair of the damaged tire to be done at home or at a tire service station. european motorists carry “spare wheels with inflated tires in the same way. the advantage of the demountable rim over the demountable wheel 1s that the spares weigh less; the advantage of the demountable wheel is that it weighs less than a wheel with a demountable rim, and especially that with it there 1s less weight near the circumference of the wheel, where it has a strong flywheel action. moreover, with the detachable wheel the detaching mechanism is at the hub, farther removed from rust-promoting influences. 980 the structure of demountable rims may be briefly described as follows: forced over the felloe of the wood wheel is a steel felloe band with a wedge surface on its outside, and an inward ilange on one edge through which end the wood felloe pass the felloe band bolts. over this felloe band is passed the rim carrying the tire, which is formed with a wedge surface on its inside, adapted to engage the wedge surface on the felloe band. rim lugs with wedge-shaped projections are threaded over the ends of the felloe band bolts, and the nuts on the bolts are then screwed up, forcing the wedges into the space be- tween the felloe band and the rim. in this way the rim is subjected to both radial and lateral pressure and is centred and firmly held on the felloe band. both clincher and detachable rims can be used in connection with demountable rims. | solid rubber tires are vulcanised on to the steel base bands, and wood wheels to be fitted with such tires have a steel felloe band shrunk over them. the tires are then mounted on the wheels in a demountable way by means of wedge rings, side flanges and bolts. cast-steel wheels generally have one wedge ring cast integral and do not need a side flange on that side. brakes.—practically all the cars manufactured up to the end of the war had brakes acting on the rear wheels only, but from that time on a rapidly increasing number were equipped with brakes acting on all four wheels. four-wheel brakes were pioneered by henri perrot, engineer of the argyll motor car co., of glas- gow, in 1910. they permit of making a stop in substantially one-half the distance as with rear-wheel brakes, thus adding to the safety of automobile travel. the minimum stopping dis- tance depends upon the pressure against the ground of the wheels through which the brakes take effect, and when the brakes are applied there is a decrease in the ground pressure of the rear wheels and an equal increase in that of the front wheels, which tends to make the front-wheel brakes particularly effective. in the application of brakes to the front wheels certain condi- tions must be met. setting of the brakes must not prevent steering motion and, vice versa, the deilection of the wheels in stecring must not change the setting of the brakes. moreover, it must be practically impossible to lock the front wheels by means of the brakes, because the car will not respond to a steering motion if the wheels do not revolve. two general types of four-wheel brake were worked out. in one the power necessary for the application of the brakes was trans- mitted entirely by mechanical means, which in the case of the front wheel brakes involved some difficulty, owing to the relative motion between brake drum and axle. it was necessary to provide a uni- versal joint in the shaft of the brake-expanding cam or the brake- band-contracting lever, whose centre lay in the axis of the steering knuckle pivot, so that steering motion of the wheels would not affect the setting of the brakes. the brakes on all four wheels were linked to the brake pedal. to obviate the danger of locking the front wheels, some designers divided the force of brake application un- equally between front and rear, usually about 40% to the front brakes, while in the perrot design the linkage was so arranged that as the front wheels were swung around in turning there was a tend- ency for the brake on the outside front wheel to release automatically, thus preventing locking of this wheel and consequent loss of control. “as regards equalisation there was absolutely no uniformity of practice in 1925. in some systems the force of application was equalised between front and rear and between right and left, while others used no equaliser at all. a mechanically operated front-wheel brake is shown in fig. 15. a is the lever to which the brake rod or fic, 15.—mechanically operated front wheel brake. motor vehicles link attaches; b, the cam-shaft; c, the cam; and h, the means of adjustment for wear. in the other type of brake referred to, the force of application was transmitted by means of a confined liquid, this type being known as the hydraulic brake. the brake at each wheel comprised a cylinder in which there were two pistons which acted upon the brake bands, or shoes, through bell cranks. these cylinders communicated through heavy hydraulic hose and copper tubing with a master cylinder within which there was a piston that was connected to the brake pedal. the whole system was filled with a liquid (a castor oil and alcohol mixture) that does not congea]l in winter and does not attack the rubber hose. pressing on the pedal forced some of the liquid from the master cylinder through the tubing into the brake cylinders, thereby forcing the two pistons in each brake cylinder apart and applying the brake. the slight loss of liquid from the system, by leakage, was made up by pumping additional liquid into it from _a reserve tank on the dashboard, provided with pump and shut-off valve. one feature of the hydraulic brake was that it was always fully equalised. with otherwise equal construction four-wheel brakes require sub- stantially twice the cffort on the part of the operator to apply them, hence persons of limited physical strength, particularly women drivers, found it hard to apply the brakes to the locking point. this jed to the development of so-called servo brakes, in which the momentum of the car was utilised to reinforce the effort of the driver in applying the brake. the simplest form of servo brake is a band brake anchored off centre, and after the adoption of four-wheel brakes most band brakes had the band so anchored that the section which tended to wrap up on the drum when checking forward mo- tion of the car was considerably longer than the other (unwrapping) section. the principle of the mechanical servo brake may be very sinply explained as follows: imagine a drum mounted on a shaft which is positively geared to the rear axle. let a rope be wound around the drum, one end of the rope being connected to the brake pedal and the other to the lever of the brake-expanding cam. then, if the operator presses on the pedal and thereby exerts a pull on the forward end of the rope and assuming the rope to be wound around the drum in the right direction, the resulting friction between rope and drum will multiply the tension in the rear end of the rope and the pull on the brake lever will be several times as great as if it were con- nected directly to the pedal. with internal or expanding brakes a servo effect was obtained by providing a floating shoe, which was pivoted to the free end of the anchored shoe. if only these two shoes were provided the brake would have very little effect in holding the car against reverse motion, and for this reason the bendix- perrot brake, illustrated in fig. 16, was made with three shoes, the fic. 16.—bendix-perrot three-shoe servo brake. third shoe being depended on mainly for checking reverse motion. some cars, notably the fiat in italy and the studebaker in america, were fitted with an hydraulic servo mechanism. this consisted of an oil pump combined with the transmission gear, which was always running as jong as the car was in motion. normally the oil was by- passed from the delivery to the suction port of the pump, and no effect was produced, but by closing a valve between these two ports by means of the brake pedal, a pressure was sct up in the system which moved a piston connected by mechanical linkage to the different brakes. if the hydraulic mechanism failed to work for any reason (owing to leakage of oil, for instance), by pressing the brake pedal down farther than required to operate the hydraulic system, the operator could apply the brakes directly by foot pressure. .\ diagram of the hydraulic servo mechanism used on fiat cars is shown in fig. 17. il. equipment there is one notable difference in the commercial practices of american and european motor-car manufacturers. in the motor vehicles united states it is customary to sell cars complete with bodies and all necessary equipment, so that upon being filled with fuel and water they can immediately take the road. the equipment usually includes such items as wind-screen, lamps, speedometer, jack, tire pump and tools. european manufacturers, on the & fic, 17,—diagram of fiat hydraulic servo brake: 1, gear type oil pump; 2, 2’, floating fevers in front wheel brake linkage; 3, delivery passage of pump; 4, servo pistons; 5, scrvo control valve; 6, brake pedal shaft; 7, gear sector on brake pedal shaft; 8, 8’, gear sectors on floating levers in rear wheel brake linkage; 9, nose on shaft 11 which engages with corresponding nose on hub of floating lever; ro, lever on brake pedal shaft to which servo control valve is connected; ii, cross shaft connected to brake pedal through lever 12 and link 13; 14,brake pedal; 15, oil by-pass; 16, cross shaft operated from brake hand lever through link 18 and lever 19. other hand, previous to the world war, often made it a practice to sell only the bare chassis and let the customer arrange for the body with a coach-builder and select the equipment himself. after the war they began to follow the american practice, espe- cially with low-priced cars. mass production—many of the cars produced in the united states were made on what is known as the assembling plan; that is, the various major components, such as engine, clutch, gearset, axles, frame, springs and steering gear, were all manufactured in different factories by concerns specialising in these products, and were assem- bled into a complete car in the assembling plant. the advantages of this plan are obvious and include the possibility of intensive develop- ment of design and the economy of quantity production. vhe extent to which assembling was practised may be judged from the following figures: of the american passenger-car models for 1920, 92%) were fitted with stock carburetters, 75° with stock steering gears, 66-7 °5 with stock clutches, 65-1 ° with stock rear axles, 58-75 with stock transmissions and 42°) with stock engines, all these stock parts being made by specialists. in the field of commercial vehicles the practice of assembling was even more prevalent. bodies,—after the war the use of closed cars increased very rapidly in the united states. previous to that time a limousine rally limited sales. qs! or any other of the closed types then in use cost substantially twice as much as the corresponding open model, and this natu- moreover, most of the earlicr closed cars were of the chauffeur-driven type, in which the driver’s seat is partitioned off the passengers’ compartment. [ndeavours to reduce the cost of production of closed bodies resulted in greatly widening the possible market for this type of car. a new low- cost design known as the coach was evolved and popularised by the iludson motor car company. it promptly met with great favour and was soon offered by a large number of manufacturers. the coach is essentially a five-passenger closed car with only iwo «loors. the seat adjacent to the driver's folds forward, thus giving access to the rear seat through the door on the right-hand side (with left-hand drive). coaches in some instances sold at prices lower than those of the corresponding open models, this being made possible by the fact that the particular maker had a much larger production on the former than on the latter. the growth in popularity of the closed car in the united states may be judged from the fact that the proportion of closed cars in the total production rose from 1.5°%o in ig1§ to 17°, in 1920, and had attained 56%) in 1925. on open or touring cars the collapsible top was to a large extent superseded by the california type or permanent top. it was found that repeated raising and taking down was quite injurious to the folding top, causing it to crease and appear shabby, and this difficulty was eliminated by the permanent construction, which also prevented sagging between bows, a common fault of old folding tops. a number of british and german makers provided a compartment in the body into which the top disappeared when folded, but generally the appearance with the top up was not all that could be desired, many attempts were made to produce double purpose or convertible open and closed bodies. in the early types the whole superstructure was removable as a unit, but this did not prove successful in the long run. in england the “all-weather” type of body became very popular. one of the first british cars to be equipped with an “ all- weather’ body was the standard, and after 1920 many other british makers fitted it. as made in england, the “ all-weather ” body comprised a regular open body with folding top and more or less rigid, transparent panels which could be used to close the sides during periods of inclement weather, these panels taking the place of the flexible side curtains with transparent inserts previously used. the transparent medium was cither glass or celluloid. usually there were a number of fairly rigid frames of flat steel, covered with fabric leather and secured to the doors and the sides of the body. the transparent element was of smaller dimensions than the supporting frame and the space in he- tween was filled with fabric leather, hence there was no possibility of the glass being broken by distortion of the body frame com- municated to the panel frame. the pancls on the docrs swung open with the latter, but in some cases they were secured by snap fasten- ings to valances on the top, and these fastenings had to be loosened first. at the front the panel was joined to the windshield pillar, and endeavours were made to have this joint rain- and draught-proof. similar joints were made between the upper edge of the panels and the top. usually there were three panels on each side, but sometimes there was a fourth at the side of the rear seat. some of these panels were so designed that they could be used as rear wind-screens when the top was down, being entirely independent of the top for support. provision was made for storing the panels inside the car, either in a tray under the front seat or in a compartment in the rear cowl, the weymann type.—a type of closed body that was distinguished by light weight, low cost of construction and freedom from squeaks was brought out by weymann in france. it had a framework of 1}-in. square wooden members which, however, were joined together by means of comparatively lizht metal strips bent to angle shape and secured with wood screws. thus the wooden members did not come in contact with cach other and the cause of squeaks was eliminated. the seats were made separate from the body and supported directly on the chassis frame, which caused the passengers to be seated lawer and permitted the body to be lower. the framework was covered with fabric leather, which was painted the same as the metal! panclled body. another advantage claimed for this construction was that it entirely eliminated ‘drumming,’ an objectionable feature of practically all closed bodies with metal panels. according to wey- mann, a four-passenger saloon body for a 130-in. wheelbase chassis built on this plan need not weigh more than 440 lb., including fenders, valances, running boards, spare-wheel carrier and tool box, which is a great deal jess than the weight of the usual open body for a car with this length of wheelbase. a disadvantage of the weymann pattern limited the designer practically to straight lines, and some of the early weymann bodies were of rather severe appearance. numerous items of equipment added to the comfort and con- venience of driver and passengers. in the united states it was cus- tomary in 1926 to equip closed cars with exhaust heaters for use in cold weather. ventilators were provided in the cowl and in the roof, or ventilation was effected by slightly raising the windshield. the windows in the doors and sides of the car could be raised and lowered at will, and with all the windows down the pussengers were as much in the open air as with an open car, while under all conditions the 982 vision was as good as from an open car with the top up. with windows closed it was impossible for the driver to give the usual signals to drivers behind by extending his arm, and this was rendered. unnecessary by providing the cars with a stop light at the rear which lit up automatically whenever the brake was applied. in case of rain or snow a section of the windshield in front of the driver's eyes was kept clear by means of a windshield cleaner, con- sisting of a swinging metal arm carrying a rubber squecgee, which was operated by hand on some of the lower-priced cars and by a vacuum engine (connected to the inlet manifold of the car engine) or by an electric motor in the majority of the models. a visor over the windshield protected the driver’s eyes against direct sunrays. the button for the signalling horn was located at the centre of the steer- ing wheel; depressing this button sounded the horn, and by turning it slightly around its axis the headlights could be dimmed to prevent annoyance from glare to on-coming drivers and could be brightened again when no one was approaching. all control instruments, some- times including an engine thermometer and a fuel-tank gauge, were conveniently and neatly arranged on the instrument board. many of the items of equipment enumcrated were also furnished on open cars. many owners had their cars fitted with bumpers at both front and rear, as a protection of the exposed parts, such as headlights, fenders, radiator, etc., in case of a minor collision. body finish—a new method of finishing motor-car bodies was introduced by one of the large american makers during the summer of 1923, and came into wide use in the industry within a short time. it consisted in giving the bodies a finishing coat of a lacquer of which pyroxylin was the base. previous to that time all the bodies built partly or wholly of wood were finished in varnish, which was open to the objections that the process of finishing was very tedious, owing to the fact that a long time had to be allowed for drying after each coat had been applied, and that the surface’ obtained was not sufficiently proof against scratching. bodies constructed entirely of metal were generally “ tlowed ” or sprayed with enamel and baked in ovens. this over- came both of the disadvantages experienced with varnish, but most of the bodies had a wooden frame and these could not be enamelled, as the wood would have been injured by the high tempcrature of the baking process; besides, with enamelling, the finish could be had only in black, as colours would have been affected by the baking heat. pyroxylin base lacquer had been used previously; but its applications had been limited, owing to certain difficulties which were overcome in 1923. the first lacquer of this type to come on the market was known as duco, but it was soon followed by many other brands. when finish- ing a body with pyroxylin base lacquer, the same priming and sur- facing coats are applied as with varnish. usually the body is given either two or three coats of the lacquer. when the last coat of lac- quer has dried it presents a so-called egg-shel! finish, and a polish is then obtained by rubbing the surface with pumice and rottenstone and applying a coat of polishing wax. a glossy surface can be ob- tained by giving the surface a coating with a clear lacquer of a pyroxylin base. to the car manufacturer the advantage of the pyroxylin finish resides chiefly in the cutting down of the time re- uired for the finishing process. aside from this saving in time and the consequent saving in the manufacturing process, pyroxylin finish makes it possible to obtain a colour finish at a moderate price, and the surface is exceedingly hard and cannot be scratched or chipped easily, while the life of the finish is several times that of a varnish-finished surface. iv. the small car owing to high licence fees (taxes) and the high cost of fuel, european makers after the war paid particular attention to the small car, as a means of reducing the cost of motoring. in the united states in 1926 the smallest car built had an r.a.c. rating of 15°6 h.p. and very few models rated at less than 20 horse-power. of the 145 british models in production that year six had a rating of less than 10 h.p. and considerably more than one-half rated at less than 15 horse-power. the cars were also built narrower. practically all american cars, even the smallest, had the stand- motor vehicles ard tread of 563 in., or at least approached it very closely, while about one-half of the british models had a tread of so in. or less, the minimum being about 43 inches. practice on the continent resembled that in great britain. the average british car of i£2-115-in. wheelbase had a h.p. rating of 12, and as the annual tax was {1 per h.p., the saving on this item was quite consid- erable, as compared with the average american car of the same wheelbase, which had a rating of 22 or 24 horse-power. with the smaller engine the fuel consumption for the same weight of car is also appreciably less, due to the fact that the load factor of the engine is higher (the average load carried is a greater fraction of the maximum output of the engine), and the efficiency of the engine increases with the load factor. on im- proved roads very good speeds could be made even with the small engines, which were always of the high-speed type (some- times called high-efficiency type). of course, acceleration was not so good, and more of the running had to be done on the lower gears, which involved more frequent gear shifting. some of the smallest cars, like the austin 7 h.p., approached a motor-cycle with side-car in power, weight and other character- istics. this vehicle had a four-cylinder engine of 55 mm. bore and 75 mm. stroke and weighed complete with 2-passenger body 790 pounds. the chief demand, however, was for the type of car rating at between 10 and 14 horse-power. among the most popular smaller cars in 1925 were the morris in england and the citroen in france. ford cars.—a unique position in the american motor-car industry has been occupied by the ford motor co., whose annual production for several years constituted about one-half that of the whole industry. this company in 1909 developed a passenger car which sold for the next 17 years without material modifica- tions in design except as regards the body and equipment. this stability of design made possible production on an unequalled scale and at remarkably low cost. in 1925 the price of the two- seater (22.5 h.p., r.a.c. rating) was $260, and that of the open 5-seater $290 f.o.b. detroit. this, however, was without the self-starter and battery lighting equipment, which were taken by practically all purchasers and which made the cost per car $85 higher. the company operated a plant at manchester, england, at which 90% of all the work of manufacture on the cars sold in great britain was said to be done. it also had a fac- tory in lyons, france, and assembling plants at copenhagen, denmark and antwerp, belgium. in 1925 the company stated that it had delivered more than 12,000,000 vehicles, and that it was then producing 7,000 per day. v. production, standardisation and marketing amazement is often expressed at the enormous capacity of the american market for absorbing cars. calculations of the limiting market were sometimes made on the premise that a certain minimum income (say $1,500 annually) was necessary in order to enable a person to keep a car, and from income-tax records the supposed number of possible owners was then deter- mined. however, these predeterminations of the so-called “ sat- uration point ” practically always erred on the conservative side. three main factors made it possible for the american people to maintain substantially 20,000,000 cars in 1926—roughly two cars for every three families (1) a great reduction in prices made possible by improved manufacturing processes; (2) the introduction of the time-sales plan and (3) the practice of many table iii. statistics of the development of the american industry 1909 1914 i9i9 1924 1925 capital invested. ... $173,837,000 $407,730,000 $1,802, 302,862 $1,691,050,112 | $1,888,028,810 cars and lorries produced!. 127,73! 569,045 1,974,016 3,617,602 4,336,754 value of products $249,202,000 $632 ,831,000 $2,506,834,594 $3,168,588,146 | $4,210,174,963 persons engaged in mfg. 85,359 145,951 651,450 629,563 711,442? wages and salaries $58,173,000 $139,453,000 $813,731,856 $547,215,700 $649,668,829° 1from u.s. census. based on statistics of complete car production gathered by national automobile chamber of commerce and on the assumption that the parts and accessorics business grew in same proportion. ?in motor-car and lorry plants alone. parts anc accessories (exclusive of tires) plants. *361,442 in motor-car and lorry plants, the rest in motor vehicles well-to-do motorists of buying a new car every second or third year and trading-in the old machine, which depressed second- hand values to a very low point. table iv. statistics of the american industry for 19251 number of passenger cars produced 3,839,902 number of lorries ae 497,452 number of open cars 1,676,171 number of closed cars od 2,103,131 wholesale value of passenger cars $2,523,642,558 wholesale value of lorries i war | as 4,202,275 parts sold by motor-vehicle manufacturers . $308,830,130 replacement parts and tires . beet al ; $92 3,440,000 total wholesale value of vehicles and parts. $4,210,174,963 number of motor vehicles exported 536,741 registrations of passenger cars 17,512,638 registrations of lorries 2,441,709 total registrations. . ; 19,954,347 number of motor-vehicle dealers 48,555 tfrom facts and figures of the automobile industry, published by the national automobile chamber of commerce. the production figures given apply to the u.s. and canada combined, practically all a the producing establishments in canada being branches of u.s. rms. the large numbers in which particularly the lower-priced american cars were manufactured made possible very economical methods of production. many parts that were formerly made of sand castings were made in the form of sheet metal pressings or die castings. both these methods of production are very much more economical, if a large number of duplicate parts is required, although the initial in- vestment for equipment, such as dies, presses, etc., is very high. in drilling the bolt holes in engine blocks, as many as one hundred holes, from top, bottom and both ends, were drilled in a single operation in a multiple spindle drill press. all the cylinder barrels of six or eight cylinder blocks were bored at the same time, and the flat surfaces on the outside of the block were finished in large milling machines, to the tables of which a large number of blocks could be strapped at the same time. machine tools of the automatic and multiple station type were largely introduced, the latter having indexing tables mak- ing it possible to load and unload the machine at one station while work was going on at one or more other stations, so that no stops were required for reloading. all the sheet metal parts, such as fend- ers, aprons, etc., when finished were hung on a conveyor which auto- matically dipped them in tanks of japan and carried them through a baking oven, so that the only hand work in the finishing process con- sisted in hanging the parts on the conveyor and taking them off again. seger bine of the car also is done on a conveyor, or moving line. the work of assembling begins with the frame, which is pulled along rails by means of the conveyor chain at the rate of 5 or 6 ft. per minute. after the axles, springs and wheels are assembled, the chassis is turned over by means of a hoist, and thenceforward is moved along on its wheels, while the rest of the parts are put on. some of the major components, such as the engine, transmission, steering gear, etc., are previously assembled on separate lines and brought to the proper point at the side of the main assembling line by means of conveyors. large use 1s made of gravity conveyors, that is, inclined planes made up of closely spaced steel rollers, which eliminate the necessity of lifting heavy parts by workmen. this is only a small selection of the methods adopted by american motor- car manufacturers which enabled them to cut down the man-hours required in the manufacture of a complete car from 1,460 in 1904 to 641 in 1914 and to 435 in 1924. the first two of the foregoing figures are based on u.s. census reports, while the last is based on statistics of the national auto- mobile chamber of commerce, a work-year in each case being taken equal to 2,500 work-hours, this does not take into account the fact that about one-half of the 1924 cars were of the closed type, as com- pared with an insignificant proportion in 1904, and all carried much more equipment. the great drop in automobile prices after the war is best illustrated by some figures gathered by the national automo- bile chamber of commerce according to which the cost of cars at the beginning of 1925 was 71° that in 1913, whereas the cost of living was 167 % and the cost of erecting frame buildings 196 %. stundardisation (see macnwine toors; measuring instru- ments).—a great help to the motor-car industry in the united states was the standardisation work of the society of automo- tive engineers, concurrent with specialisation in the manufacture of parts. one of the first things standardised was fine-pitch screw threads. it was found that the former standard threads, such as the u.s.s., whitworth, etc., were too coarse for motor- car work, and manufacturers began devising their own fine- thread standards; if this had continued it would have led to the use of many different pitches for screws of the same diameter, which would have been most annoying to the user. in order to 983 obviate this, the s.a.e. screw thread was evolved, and soon came into common use. a great deal of the standardisation work was concerned with the joints or connections between parts made in different factories. thus the mountings, on the engine, of carbu- rettors, battery ignition units, magnetos, electric generators, starters and tire pumps were standardised, as were flywheel housings, shaft fittings, spring mountings, etc. at the end of 1924 there were more than 200 separate motor-car standards on the records of the s.a.e. great britain had a similar technical society, the institution of automobile engineers, but motor- car standardisation work was carried on by a sub-committee of the british engineering standards committee, on which both the institution of automobile engineers and the society of motor manufacturers and traders were represented. there was also a technical society in germany, the automobil und flugtechnische gesellschaft, but it had not been active. during the world war engineering standardisation work was begun in germany by a general organisation covering the whole engineer- ing trade, and after the war motor-car standardisation was con- tinued by the reichsverband der automobil-industrie. vi. depreciation and insurance a private car naturally is most enjoyable during the first years of its life, while it is still fairly representative of the highest advance of the art, while its finish is unmarred, its mechanism runs smoothly and quietly and while the chances of breakdowns on the road are at a minimum. therefore, many american motorists ‘‘ trade in ” their cars every second or third year for new ones. the average american automobile built prior to 1920 had a life of about 7 years, so the average depreciation was slightly less than 14%, the car having still some “‘ junk ” value at the end of its useful life. however, during the first few years the depreciation was much greater. the “ used-car prob- lem”? became a great bugbear to the american industry and trade. very few cars of the better grades were operated by their original owners until worn out, hence in the case of practically every sale of a new car an old one had to be taken in, and in their eagerness to effect a sale, dealers often made a greater allowance than the condition of the car and the state of the market warranted. this was reflected in the high rate of “‘ mortality’ among automobile dealers, which reached 25% in 1922 and 26% in 1923 but declined to 21% in 1924. for the guidance of dealers the chicago automobile trade assn. published an index of used car values which circulated throughout the country. from this it was found that the values of a car at the end of successive ycars of service formed substantially a geometrical series and that the value at the end of the year on the average was only slightly more than 50% than at the beginning of the year. after the first few years the higher grade cars depreciated somewhat less rapidly than the lower grades. in the following table are given the valuations of the 1919-24 models of three makes of car—high, medium and low-priced, respectively—during the second quarter of 1925. used-car values year of manufacture | 1924 | 1923 | 1922 | 1921 | 1920 | i919 original cost . | 9,000 | 7,000 | 7,000 | 9,000 | 9,500 $e value in may 1925 2,300 | 1,700 |} 1,200 | 850 150 original cost . 965 | 1,195 | 1,395 | 1,795 | 1,595 as value in may 1925 385'| 275 185 175 75 35 original cost . 510 | 525 | 525 525 795 value in may 1925 255} 1950 go 50 25 10 1 this exceptionally high depreciation was due to the fact that the particular model was discontinued by the manufacturer. the rate of depreciation in general also was affected by the fact that from 1920 on new car prices decreased materially. the above table shows that the item of depreciation during the latter years of a car’s service is very small. the life of a car naturally is a matter of considerable moment ta both the owner and manufacturer. the assertion has been made that there is no limit to the possible life, as all parts are interchangeable, 984 and any part that wears out can be replaced by a new one. there is an element of truth in this statement, and it is quite pos- sible to obtain phenomenal mileages if that is desired above every- thing else. in practice users find that after a car has given a certain amount of service it is best to “‘ scrap’ it and get a new one. with increasing age the cost for repairs increases rather rapidly, the car becomes ‘“‘rattly’’ and therefore less pleasant to operate, it usually becomes shabby in appearance, and besides, it docs not possess the improvements of the newer models making for increased comfort and convenience of the occupants. when a certain state of deprecia- tion and obsolescence has been reached, the car therefore usually goes to the ‘‘ auto-wrecker,”’ who takes it apart and sells some of the parts for repairs to other old models and the rest for scrap metal. since there are available in the united states fairly accurate sta- tistics of annual production, registrations (cars in use), exports and imports, it is possible to calculate quite closcly the average age of the cars which have been scrapped. each year there are newly put into service a number of cars which is equal to the number produced in the country that year, minus the number exported, plus the num- ber imported. if no cars were scrapped, then the total number of registrations would be increased in the course of the year by the number newly placed in service. actually the increase in registra- tions will be less, and the difference between the number of cars newly placed in service in any year and the gain in registrations during that year is the number of cars scrapped during the year. the average life is then substantially equal to the interval between the one-year period during which an equal number of cars was newly placed in service and the year during which the cars went out of service. some correction must be made for the fact that the going into service of all cars does not coincide with the beginning of the year in which they were first registered. by the use of this method it was found that the average life of all cars which were scrapped in the united states during the three-year period ending with 1923 was 6.9 years. car thefts—after the war the loss of motor-cars by theft became a serious hazard, which is partly accounted for by the fact that by that time cars had become so numerous that prac- tically the whole of the younger generation had the opportunity to learn their operation. there were two general forms of automobile thievery. one form, indulged in particularly by irresponsible youngsters, con- sisted in taking a car that was left by its owner at the curb, going for a “‘ joy ride” and leaving it at the roadside wherever the fuel supply ran out, an accident occurred or something else intervened to compel the abandonment of the trip. ‘the more serious form was theft of cars with a view to their sale to the public. the division of the united states into a large number of states, each with its own laws and police powers, facilitated this nefarious business, and there grew up a regular traflic in stolen cars that were driven over the border into a neighbouring state and there disposed of by unscrupulous dealers. the matter became so serious that the federal govt. in 191g passed the dyer act, which made it illegal to transport or assist in the transportation of a stolen car from one state into another. another measure that hit at the root of the evil was the en- actment, by several of the states, of laws requiring an abstract of the title to be filed with the authorities, as in the case of real- estate transfers. all cars were provided with locks, which acted as more or less efficient theft retardants. the ignition type, which came into use first, proved of little value, as a man skilled in electrical work and familiar with the particular car could read- ily make or unmake the necessary connections to render it inef- fective. locks on the transmission were more dependable, but when these were introduced it was found that owners often failed to lock them, as they were generally rather hard to get at. it was then suggested by the insurance underwriters that “ con- current ” locks be fitted, acting on both the ignition switch and on the transmission, which the owner was compelled to lock if he wanted to shut down his engine, and these were coming into use in 1925. in 1924, 10,064 cars were stolen in new york city, of which 7,101 were recovered. | insurance.—motor-car insurance had grown to a very large business in 1925. the insurance companies wrote policies covering five principal hazards, namely, fire, theft, collision, lability for per- sonal injury and liability for property damage, but usually several or even all of these were covered by a single policy. reductions were made on the premium for carrying certain equipment which had been approved by the underwriters’ laboratories, lor instance, a reduc- tion on the premium on fire insurance was granted if a portable fire extinguisher was carried on the car; on theft insurance, ii the car had motor vehicles an approved lock and on collision insurance, if it was fitted with approved bumpers. according to the insurance field, the total premiums paid in the united states under the five principal hazards during 1924 amounted to $297,005,029, and the total losses reported were $123,292,454. during the period when the “ jitney ”’ business was increasing rapidly and many taxi-cabs were operated by individual owners, the operators often caused serious accidents and then were unable to pay the damages awarded by the courts to the injured. many cities and states then passed legislative measures requiring all operators of public-service vehicles to be bonded or to carry insurance. later, attempts were made to extend this compulsory insurance plan so as to apply also to drivers of private vehicles, and in 1924 bills to that effect were introduced in the legislature of six states, but none passed that year. switzerland and denmark at that time had com- pulsory insurance of motor-car operators. in switzerland any appli- cant for a driver's licence was compelled to take out first a liability insurance policy for a minimum indemnity of 30,000 fr. to a single person and 100,000 fr. to several persons. for motor-cycles the amount was 20,000 francs. under the swiss law the driver and not the owner of the vehicle involved was held responsible for the damage done. however, the burden of proving intention, negligence or im- pru:lence rested with the claimant. an attempt was made while the bill was under discussion to make motorists directly responsible for all damage done by their cars, the same as in the case of the railways, but this was strongly and success- fully opposed by the motoring interests. tourists when entering switzerland were compelled to arrange for insurance for the dura- tion of their stay in the country. the danish law went into effect in 1918 and was amended in 1921. under it, motorists were com- pelled to take out a policy for 20,000 crowns and motor-cyclists for 10,000 crowns. the objection was raised to the compulsory in- surance scheme that it would have the effect of making drivers careless. insurance companies opposed it because most of the plans involved the feature of state insurance. vii. accidents and legislation a rather unpleasant chapter in motor-car history is that of accidents. with the constantly growing number of cars on the road and the increasing speed of their operation, it is natural that accidents should have increased, but after the world war the figures became appalling. many measures were taken to reduce the hazards, and a certain degree of success was achieved, in that the number of accidents in proportion to the number of cars in service decreased, but still the total number increased from year to year. at first a large proportion of the accidents occurred in the cities, as most of the cars were then owned there, and many factors, such as congestion of traffic, lack of play- grounds for children, etc., contributed to the hazards. means of traffic regulation were introduced which not only tended to prevent accidents but greatly speeded up traflic (see traffic problems). in all of the large cities in 1925 a large proportion of the police force was detailed to traffic duty. they were stationed at all main street intersections, and let the traffic pass alternately in the two directions. safety zones and isles of safety were marked off by lines painted on the pavement, or by other means, where people could wait safely for tramecars or take refuge in crossing wide streets. some of the narrower streets were reserved for trathc in one direction only. in the smaller places, where the expense rendered it impractical to station traffic policemen at important crossings, beacon lights were placed on the ground at the centre of the crossing, some of them so arranged that they became extinguished automatically in broad day- light, and later automatic traffic signals were installed which, by showing red and green lights alternately in the same direction and simultaneously in the two directions at right angles to each other, served the same function as the traffic officer and were sometimes referred to as silent policemen. a large number of (usually very serious) accidents occurred at railway crossings, and relicf from this hazard was sought by the climination of level crossings and by pro- viding guards at points of intense trathe and more effective warning signals at others. notwithstanding all these safety measures and the institution of campaigns of education the number of automobile fatalities in the united states increased from 9,097 in 1917 to 12,370 in 1921 and to 17,345 in 1924. ‘these figures are of the same order as the american losses in the world war, and the comparison was made use of to bring home the seriousness of the situation. fatalities per 100,000 cars in service in the three years mentioned were 178, 118 and 98 respectively. automobile grade-crossing fatalities increased from 1,791 in 1920 to 2,149 in 1924, or at a lower rate than automobile fatalities generally. in european countries there was a similar in- crease in accidents, although, on account of the lesser density of motor traffic there, the figures are less striking. in paris, for instance, the number of street accidents increased from 70,715 1n 1922 to motor vehicles 126,867 in 1924. an analysis of the causes of accidents involving motor-cars was made by the motor vehicle dept. of the state of connecticut in 1923. out of a total of 15,170 accidents, 70-5 °% were the fault of the operator, 22-8 % the fault of other persons, 4°% were due to defective equipment and 2:7°%% to all other causes com- bined. of 834 accidents in connecticut in jan. and feb. 1924, for which the operators were held responsible, 36:8°% were duc to failure to give right of way (disregard of the rules of the road): 13-7 % to skidding; 13-5 °o to inattention; 6-7 °6 to failure to signal; 6° to careless backing; 5-4°> to excessive speed for the conditions; 5-3 °% to allowing too little headway; 3-1 % to driving on wrong sicle of road; 2-4. % to confusion; 1-8 %% to cutting in; 1-7 % to inexperience; i-t “5 to intoxication; 1° to cutting corners; 1.5% miscellaneous. dr. c. h. dickinson of the bureau of standards suggested as one rule of safe driving that the speed should never be so high that the car can- not be stopped within the assured clear course ahead. legal history.—during the first decade of the 20th century the development of the motor-car industry in the united states was hampered to a certain extent by attempts to enforce recognition of an alleged basic patent on vehicles propelled by liquid hydro- carbon engines, which was issued to george b. selden, of roches- ter, n.y., in 1895, after having been in the patent office since 1877, but in sept. 1911 the u.s. circuit court of appeals for the second circuit held that, although the patent was valid, it was not infringed by the defendant, the ford motor co., which implied that it was not being infringed by any of the car manu- facturers in production at that time. the assn. of licensed automobile manufacturers (a.l.a.m.), consisting of the manu- facturers who had recognised the patent prior to its defeat in court, then reorganised as the national automobile chamber of commerce, which came to be recognised as representative of the entire automobile industry, although the ford motor co., the largest manufacturing concern, never joined it. all the national motor-car shows in the united states from that time till 1925 were held under its auspices, and it looked after the interests of the industry also in other ways, particularly through its legal, trafic and patent departments. patent litigation in the industry was practically entirely prevented by a cross-licensing agreement involving all members of the chamber. similar organisations in other countries are:— great britain.—society of motor manufacturers and traders. france.—chambre syndicale de l’automohile et des industries qui s’y rattachent. belgium.—chambre syndicale de l’automobile. germany.— reichsverband der automobil-industrie. viii. motor racing and shows during the years immediately preceding the world war france had the greatest export business in motor-cars, built up by consistent technical development and skilful sales propa- ganda, chiefly in the form of road-racing. a series of interna- tional races held during the first decade of the century, known as the gordon bennett cup races, came to an end because the french objected to the stipulation in the deed of gift of the cup that in the race each country should be represented by a team of three cars, which gave a country with a small industry practically the same chance of winning as a country with a large industry. in rg1r began a new series of races for the grand prix of the automobile club of france in which each manufacturer was allowed to enter up to three cars, and there was no limit to the number of manufacturers of any one nation. in fact, the race was not on the basis of national team against national team, but on that of manufacturer against manufacturer. this race was held four vears in succession (tgr1—4) and was revived in 1921. owing to the continued improvement in engines and the increased speeds made possible thereby, it was repeatedly neces- sary to reduce the limit on the piston displacement of competing cars. originally the displacement was limited to that of a four- cylinder engine of r10-mm. bore and 200-mm. stroke (7-6 litres), but in ro2t the limit was 3 litres, in 1923 it was reduced to 2 litres and in 1925 to 1-5 litres (for the 1926 season). in england and scotland racing on the public roads was pro- hibited, and the only road races in the british is. were held in the i. of man. in the united states a number of important 985 races were held in the east during the early years of the automo- bile movement, but owing to frequent fatalities a strong public sentiment grew up against them, and race promoters were com- pelled to shift the scene of their activities first to the south and then to the middle west and far west. between ro1o and 1914 a number of racing-tracks with high banking, most of them 23 m. in circumference, were built in the united states after the model of the brooklands track in eng- land. the first and most successful of these was the indianapolis speedway. it was at first attempted to hold races on these tracks at frequent intervals, but they soon began to pall on the public. later the plan of a single annual race was adopted, european contestants were secured, and large cash prizes were offered to the winners, and from that time the indianapolis races have always had an enormous attendance. it is worthy of note, how- ever, that practically none of the large manufacturers of america entered cars in the later races. in earlier years competition in races was regarded as a form of sales propaganda, and the ex- penses were charged to advertising, but the public gradually came to realise that to win a race at close to 100 m.p.h. required an entirely different car from that needed by the average family, and that it would not be safe to base conclusions regarding the quality of a company’s stock cars on the performance of its special racing machines. track-racing then became a form of entertainment, expenses being met out of gate-money. the indianapolis speedway 5o00-m. race held on decoration day, 1925, was won by peter depaolo on a 2-litre (122 cu. in.) eight- cylinder-in-line duesenberg racing car with supercharger, at an average speed of ro1-13 miles per hour. shows.—an important influence on the rapid development of the motor-vehicle industry must be ascribed to the motor-car shows held annually (except for interruptions due to the world war) in such centres as paris, london, brussels, new york and chicago, under the auspices and control of the motor-car manufacturers’ associations of the respective countries. the paris show, the oldest and for a long time the largest as regards number of exhibitors, was resumed after the war, to19. but in 1920 the show was suspended, because at the time when prepara- tions would have been made trade conditions seemed to make it unnecessary. it was again suspended in 1925. london shows were held at olympia. owing to the fact that great britain was one of the greatest markets for motor-cars, importing more than any other country in europe, the olympia show always had a strong international flavour. there was a special show for commercial cars at olympia in 1923, shortly after the passenger- car show. in the united states also, truck shows had been held separately for several years. national motor-car manufacturers’ associations previous to the world war had an international federation with headquarters in paris. in 1920 the original international federation was dissolved, and a new allied federation took its place. the antomobile association.—a unique organisation of mo- torists, the automobile association, exists in great britain, and in 1925 had over 300,000 members. when the association was organised in 1905, motorists were using their vehicles under considerable difficulties, and the police authorities of practically every county in the united kingdom made a special point of seeing that the speed limit of 20 m.p.h. was strictly adhered to. among the services which this organisation rendered to mem- bers were the following: free assistance by its patrols, which were found on 20,000 m. of the main highways of the covatry; free legal defence in proceedings under the motor-car act and the roads act in any court of summary jurisdiction in the united kingdom; free use of roadside telephone boxes at any hour of the day or night; free legal advice on any matter arising directly out of the use of motor-cars or motor-cvcles; free advice and assistance by the home and foreign touring departments of the association; access to roadside motor fuel supply stations; engt- neering advice on matters appertaining to the purchase, repair and maintenance of cars and motor-cycles; officially appointed agents and repairers, as well as hotels, in practically every town in great britain, where the facilities and accommodation offered 986 had been inspected and approved by the association. the uni- formed patrols of the a.a., which saluted every passing member (but failed to salute if they wished to give a warning or communi- cate with the member for any reason) are a familiar sight on british highways. the association also had an industrial vehicle section which, among other services, endeavoured to secure return loads for motor-lorries making deliveries to remote points. ix. motor taxation in nearly all countries motor vehicles are subject to an annual tax based upon the rated horse-power of the engine. great britain did not impose such a tax until jan. 1 1921. the rate was then {1 per horse-power, determined by the following equation :— h.p,. =—— 2°5 where n is the number of cylinders and b the bore in inches. the same formula, known in great britain as the royal automobile club formula, was used in most states of the united states, where it was known as the a.l.a.m. formula. since the war the u.s. govt. levied an excise tax on all cars turned out by the manufacturers as well as on repair parts and tires sold. this tax in 1924 netted the govt. $101,123,621-75 from passenger cars, $10,335,369-14 from commercial vehicles and $27,742,764-12 from parts, tires and accessories. vehicles for hire also were subject to a federal tax, which netted $2,013,839:00, making the total federal receipts from motor vehicles in 1925, $141,215,594-01. registration fees, including drivers’ licence fees, which were collected by the states, totalled $225,492,252-00 (an average of $12-82 per car). some of the states collected a tax on petrol. it was estimated by the u.s. bureau of public roads that per- sonal property taxes on motor vehicles amounted to $90,000,000, and by the national automobile chamber of commerce that munic- ipal taxes of $15,000,000 were levied, making the total taxes derived from motor vehicles by the federal, state and municipal govern- ments in 1925, $551,442,336-01. annual taxes. are much higher in great britain. for a total of 1,393,000 licences current on march 31 1925, aggregate fees of £13,437,000 were paid, or an average of a little less than {10. this average figure, however, is greatly in- fluenced by the large number of lightly taxed motor-cycles licensed. the average fees paid on public-service vehicles amounted to £31 9s.; for commercial goods vehicles, {21 1s. 6d.; for motor-cars taxed on a horse-power basis, {15 8s., and for motor-cycles, {2 13s. 6d. several other classes figure in the tax records, including motor-ploughs, and motor-tractors, but they are taxed rather lightly. x. world commerce during the early part of the world war the american motor industry furnished large numbers of motor-lorries to the british, french and russian governments, as reflected by the export returns, which showed an increase in the number of trucks ex- ported from 784 in 1914 to 21,265 in 1916. at the same time the foreign demand for american passenger cars increased greatly, because the belligerent european countries could not make deliveries. in 1918, when the united states threw its full strength table v. u.s. motor-car exports (including passenger cars, lorries and parts except metor-car engines and tires) exported to 1924 | i9i9 iqi4 belgium?! . 9,472,635 364,004 160,659 denmark !. 8,930,388 | 4,443,302 184,951 france 4,980,144 | 22,243,042 | 1,103,481 germany . ‘ 2,927,029 si 1,272,600 great britain . 10,305,752 | 9,760,430 | 7,159,074 italy . 2,245,575 215,417 293,275 norway 545,525 | 2,102,757 124,083 russia 167,826 8,292 917,859 spain 6,322,196 1,426,650 71,024 sweden 31432,040 689,998 260,228 canada! 27,824,520 | 22,062,779 | 9,583,655 argentina 17,842,193 | 4,492,522 120474 brazil 10,204,507 1,033,831 370,043 chile . 2,313,463 | 2,606,047 192,342 british india ; 2,363,963 543,393 439,968 dutch east indies . 1,399,961 4,498,397 238,322 japan : ; 5,710,461 6,416,928 137,522 australia . 33,594,710 | 5,358,336 855,037 new zealand 5,406,913 | 2,589,166 | 1,089,951 br, so. africa 7,627,583 | 2,568,790 | 1,506,668 other countries 41,765,611 | 20,272,577 | 6,215,990 205,382,995 |11 3,696,658 | 33,298,806 1 exports to these countries in 1924 consisted largely of parts which were there assembled into cars of which a considerable proportion were exported to neighbouring or politically allied countries. totals motor vehicles into the war, motor-car exports suffered a material decline, but they jumped ahead again immediately after the armistice, an increase of 79% being shown in 1919. that year the exports of passenger cars, lorries and parts together exceeded $100,000,000 in value, yet the passenger cars exported were hardly 4% of the total production, while the exports of commercial vehicles amounted to 4:9%. after the war the tide of international motor-car com- merce showed great fluctuations. as soon as shipping connec- tions became re-established there was a heavy demand, particu- larly from the neutral countries of northern europe. in ro1g only the united states was in a position to export large numbers of vehicles, because it took the motor-car industries of the euro- pean belligerents a long time to get back to a peace basis. after a short time, however, the low rates of continental exchange table vi. british motor-vehicle imports 1924 1920 i915 igio : £ cars _ 6,322,121 | 3,028,427 | 10,490,012 | 3,128,229 | 1,440,586 chassis | 2,204,443] 1,759,321] 4,254,949 | 1,135,146 | 1,670,969 parts'. | 2,734,284 | 3,342,255| 8,713,684 | 2,183,184 | 2,023,273 totals | 11,260,848 | 8,130,003 | 23,458,645 | 6,446,559 | 5,134,828 1exclusive of tires. table vii. british motor-vehicle exports £ £ £ £ cars 5,065,308 | 3,685,054 | 3,929,455 | 1,129,717 | 1,380,190 chassis 2,347,284 | 1,176,006 | 2,474,877 186,691 213,378 parts! .| 2,009,147 | 1,652,506| 1,986,410 557,869 | 1,012,835 totals! 9,421,739 | 6,513,566 | 8,390,742 | 1,874,277 | 2,606,403 1 exclusive of tires. the number of motor-cars, lorries, chassis and parts imported into great britain in 1925 was 50,339; the number exported 29,051. according to a report made by the society of motor manu- facturers and traders to the board of trade early in 1926, about 1,000 concerns were then engaged in the manufacture and the wholesale distribution of motor-cars in great britain, and the amount of capital invested in the british industry was about {£50,000,000. the number of retailers was placed at 12,000. and embargoes on motor-car imports in several countries, in- cluding great britain, france, germany, italy, denmark and norway, cut down the exports from the united states. even when the embargoes were lifted, imports were restricted by high customs duties, as, for instance, 70% in the case of france. the german embargo was lifted on oct. 1 1925 but imports of cars were subject to an import duty, which, starting with rather high rates, was to be reduced every six months until in 1928 it was to be stabilised at substantially the pre-war rates. for a number of years previous to 1925 germany had special agreements with austria and italy whereby she allowed a cer- tain number of motor-cars to be imported from these countries in return for permission to export to them german motor-car parts, such as magnetos and ball-bearings. imports of cars from other countries were made possible by special permits, but per- mits for only four cars per make per month were issued. imports into france were rendered practically impossible by the high duty, while great britain continued to absorb large numbers of foreign cars even during the period the mckenna duties were in force. the removal of these duties by the labour govt. sub- jected the british industry to a severe strain, especialy on account of competition from the united states, but it was ob- served by german commentators in 1925, who then feared a similar ordeal for their home industry, in view of the contem- plated lifting of the embargo, that the british industry had suc- cessfully met this competition. xi. commercial motor vehicles up to 1920 motor-omnibuses were developed chiefly for city transport, and the two largest operating companies at that time were the london general omnibus co. and the corresponding ae motor vehicles paris corporation, the societe des transports en commun, the former operating a fleet of 2,500 vehicles. omnibuses for city use are generally of the double-deck type, designed to carry a maximum number of passengers at a moderate speed but to have good accelerating power. in 1926 the london general omnibus company, in alliance with the associated equipment company, placed on the streets a new series (200 vehicles) which was fitted into a covered top and was therefore specially designed and sprung to meet the police regulations. this type was 13 ft. 104 in. high, 25 ft. long, 7 ft. wide and had a wheel base of 15 ft. 6in. the vehicles are licensed to carry 50 passengers, 24 inside and 26outside. in the united states the yellow coach mfg. co. turned out a double-deck ’bus for 67 passengers, which had a wheelbase of 200 in. and a tread of 733 in., a chassis weight of 7,313 lb. and carried a four-cylinder 4 by 6-in. engine. omni- buses with petrol engines and electric drive came into extensive use in the united states in 1925. two hundred of these were placed in service by the street railway management of phila- delphia, and smaller numbers by operating concerns in other cities. "buses and lorries with electric drive without the use of a storage battery had long been made by tilling-stevens, ltd., of maidstone, england, and in the united states the general electric co. had been working on the problem. one disadvan- tage of the earlier designs was that, owing to the slowness of an electric generator to “‘ pick up,”’ that is, to attain its full voltage, if the throttle of the engine were opened quickly the engine would be without appreciable load for an instant and would race, which would result in vibration very unpleasant to the passengers. this was overcome by providing a separate exciter for the generator, the field of the exciter being supplied with battery current. an advantage of the electric drive in urban omnibus service, where frequent starts and stops must be made, is that acceleration is much smoother, there being no interrup- tion due to gear-shifting. the strain on the driver is much less, as practically all speed control is effected by means of the throt- tle. shocks to the mechanism due to “ grabbing ” of the clutch when shifting gears are avoided, and it was also claimed that better schedule time could be made than with a similar omnibus with mechanical drive. | development in the united states; new types —a great exten- sion took place in rural omnibus services between 1920 and 192s. in the united states this was strongly influenced by the rapid extension of the network of improved roads, which made it possible to operate the vehicles at lower cost, but there were parallel developments in many other parts of the world. the earlier omnibuses generally were shod with solid rubber tires, had stiff chassis springs designed to withstand the shocks sus- tained on rough roads and generally had a high centre of gravity, which features combined to make riding in them rather uncom- fortable. about 1923 a new type of omnibus, referred to as a safety coach, made its appearance. it was mounted on pneu- matic tires, had a wide tread and a very low-hung chassis, some- times was equipped with air brakes and had sufficient power for speeds up to 60 m.p.h. on smooth, level roads. some of these vehicles were as luxuriously equipped as, and afforded all the comfort of, the finest private closed cars, while others, for a differ- ent class of service, were of less pretentious construction. one development in the omnibus field that came to the front in 1924 was the six-wheeler. these ‘buses had double axle rear trucks and were driven and “ braked ”’ on the four wheels. dis- tribution of the total weight on six wheels facilitated the use of pneumatic tires. with the increase in size and speed of the *buses, increased power was required, and whereas most of the earlier omnibuses in rural service had four-cylinder engines (they were actually, for the most part, adapted lorry chassis), in 1925 more than one-half of the omnibus models offered by american manufacturers had six-cylinder engines, which offered advantages also from the point of view of reduced vibration. the frame height of the loaded omnibus from the ground generally varied between 22 and 26 in., and most of the larger and faster vehicles were equipped with four-wheel brakes. rural omnibuses were 987 generally of the one-man type, passengers entering through a door at the front and depositing their fare in a coin box near the driver, while entering or leaving. the door was of the safety type which could be opened and closed only by means of a lever within convenient reach of the driver’s seat. a mirror in front of the driver enabled him to observe the passengers without losing sight of the road ahead for more than an instant. electric buttons at the sides of all seats enabled passengers to signal the driver when they wanted to get off, and at night the interior of the vehicle was usually brilliantly lighted. in the ordinary low-fare ’buses the seats were often of the plain, cane-covered type, while those for a more exclusive service generally had deep- ly upholstered or even air-cushioned luxurious seats and some- times revolving chairs. in 1925 it was estimated that there were 60,000 motor-omnibuses in service in the united states, including 31,100 by independent common carriers, 3,250 by tramway companies, 20,000 by schools, i 500 by sight-seeing and tourist undertakings, 2,900 1n various lines of business {real estate, department stores, apartment houses, ga-. rages and factories), 1,000 by hotels and 250 by railway terminal companies. the motor-omnibus was responsible for important changes in the educational system. in 1924, 1,424 consolidations of schools took place, and that year some 470,000 pupils were daily carried to and from school in motor vehicles, ~ lorries.—motor-trucks must be equipped with engines able to take them fully loaded up the steepest grades which occur on regularly travelled highways. when operated in comparatively level districts they always have a surplus of power, and it was found advantageous when operating under such conditions to use one or two trailers with the truck. the advantage is greatest where the merchandise to be transported is very bulky. this plan results in considerable economy, as from two to three times as much load can be carried on one trip as with the truck alone, with little extra expense. in continental europe there was usually a helper on each trailer to look after the load and apply the brakes, but the use of helpers greatly reduces the gain in economy, especially where wages are high, and in the united states it was not usual to employ an extra man. it was realised that in order to make it possible to stop in an emergency the trailers as well as the truck must be braked; but the problem of braking the trailers from the truck had not been definitely solved although at least one system of air brakes and one system of automatic mechanical brakes applied through the drawbar had been worked out. another combination for heavy merchandise transportation consisted of a road tractor, which was merely a foreshortened truck chassis, and a semi-trailer. this semi-trailer was a two-wheeled construction, the forward end of which was supported on the tractor frame by means of a swivelling fifth wheel. this end of the semi-trailer could be sup- ported by means of jacks while loading and unloading, and the tractor did not need to stand idle while these operations were go- ing on. a particular form of semi-trailer was the pole trailer— the length of which could be varied—used mainly for transport- ing lumber, pipes, steel sections, etc. electric and steam vehicles.—in 1925 electric and steam pas- senger vehicles formed an insignificant fraction of the whole num- ber in use. previous to the war the electric passenger car had considerable vogue as a ladies’ car, especially in cities with com- paratively level streets, like los angeles, chicago, cleveland and buffalo in the united states, but the introduction of the electric starter, and, to a lesser extent, the demountable rim, re- moved the last obstacles to the use of petrol cars by women drivers, and thereafter the electric passed into the background. on the other hand, electric lorries had found a definite place in city haulage, particularly in new york, where at the beginning of 1925 3,274 such lorries were in service. owing to the low power of their motors the depreciation of these lorries was low and the cost of transportation with them on a ton-mile basis was somewhat less than with petrol lorries, but on account of its greater independence and its materially greater speed, most users preferred the petrol lorry even for city haulage. a new type of electric commercial vehicle, known in the united states as an industrial truck, but perhaps better described as a 988 floor truck or a low-wheel truck, came into extensive use, espe- cially during the war period. these industrial trucks take the place of hand trucks on steamship piers and railway-station platforms, in factory buildings and paved yards. petrol industrial trucks have also been developed, but as they are not admitted to steamship piers on account of the fire hazards, the electric has an undisputed field there. there was great inducement in europe during the war, when petrol was exceedingly scarce, to develop the electric vehicle for both passenger and commercial traffic. in germany a scheme was worked out for a system of goods transport in large cities by electric lorries with interchange- able batteries, and a few sample trucks were built, but the armistice intervened and the scheme was dropped. the steam vehicle also retrogressed as a factor in transporta- tion. in 1925 the manufacture of steam passenger cars had almost entirely ceased, but considerable numbers of steam lorries were still being manufactured in england. the petrol motor had definitely gained the ascendancy over steam and electric motors, and supplies for it could be found and repairs to it had in almost every town. in the united states, for instance, there were, at the beginning of 1925, 65,674 repair shops (besides 58,206 garages), and all these repair shops were equipped to cater to owners of petrol cars, but only a few to owners of steam and electric vehicles, giving a tremendous advantage to the former. brbpliography,—a, g. clark, textbook on motorcar engineering, 2 vol. (tgtt and 1917); h. l. arnold and f. l. faurote, ford afethods and ford shops (1915); s. v. norton, the afotor truck as an slid to business profits (1918); p. m. heldt, the gasoline automobile, 4 vol. (1920-5); w. h. berry, \fodern motor car practice (1921); j. c. wright, automotive repairs, 4 vol. (1921-3); h.r. ricardo, the internal combustion engine (1) slow speed engines (2) iligh speed engines (1923); p. m. stone, electricity and its .ipplications to automotive vehicles (1923); h. j. butler, \oter body-work (1924); b. g. elliott, automobile repairing (1924); g. w. grupp, economties of motor transportation (1924); g. d. angle, engine dynamics and crankshaft design (1925); r. bussien, automobiltechnisches handbuch (1925); e. l. consoliver, automotive electricity (1925); c. haniland, das motorrad und seine konstruktion (1925); r. hauer and g. hi. scragg, bus operating practice (1925). national automobile cham- ber of commerce, facts and figures of the automobile industry (an- nual). (p. m. il) motta, giuseppe (1871- ), swiss statesman, was born at airolo dec. 29 1871. he studied law at the universities of fribourg and munich and at heidelberg and became a successful barrister, establishing an extensive practice in ticino and the neighbouring cantons. he served on the great council from 1895-tg1tr and was 2 national councillor from 1899-1911. he led the catholic conservative party in the ticino from 1go00 to r91t and on dec. 14 of the latter year was elected a member of the federal council by the federal assembly. in 191g and 1920 he was president of the swiss confederation. he directed the financial administration of the confederation 1912-9, and in 1920 assumed charge of the federal dept. of foreign affairs. motta was chief of the swiss delegation to the league of nations in 1920 and presided over the fifth assembly of the league in 1924. | mottl, felix (1856-1911), german conductor (see 18.931), died at munich july 1 rorr. moulton of bank, john fletcher moulton, baron (1844-1921), british lawyer, was bern at madeley, salop, nov. 18 1844. educated at kingswood school, bath, and st. john’s college, cambridge, he had a brilliant career, becoming senior wrangler and first smith’s prizeman in 1868. he was elected a fellow of christ’s college, and in 1874 was called to the bar. he specialised in patent law, for which his conspicuous scientific abilities peculiarly qualified him, and rapidly acquired a large and lucrative practice. in 1885 he became a q.c. and entered parliament as liberal member for the clapham division of london. in the following year, however, he lost his seat and was out of parliament until 1894, when he succeeded sir charles russell, q.c. (lord russell of killowen), as member for south hackney. he was unsuccessful at the general election of 1895, but in 1898 he was elected for the launceston division of corn- wall, a seat which he retained until his appointment as a lord justice of appeal in 1906. in 1912 he was made a lord of appeal motta—mountaineering in ordinary with the title of lord moulton of bank. he died suddenly in london, march 9 1921. owing to his combination of gifts, moulton’s position at the patent bar was unique. he had no rival and has had no suc- cessor. as a judge his success was less pronouneed, perhaps in consequence of the extreme specialism of his career as a practi- tioner. on the other hand, during his years on the bench, he rendered distinguished scientific service to the country. he was first chairman of the medical research committee under the national insurance act (1912) and during the world war he was chairman of the committee on chemical products and high explosives and director general of explosive supplies in the ministry of munitions. he also was chairman of the british dyestuffs corporation (191g). mounet-sully, jean (1841-1916), 18.936), died in paris march 1 10916. tragedien was pubhshed in ro17.