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[Cecil Clutton’s historical surveys are widely respected for their interest and accuracy, and we have great pleasure in presenting this account of racing car evolution over a period which, up to now, has been given very meagre attention—Ed.1 LIKE “1066 and All That,” motor racing design has moved in waves. The first wave, frOm1895 to 1901 ,.marked the experimental stage : the gradual standardization of design. 1902 to 1907 was the period of brute force, when monsters reigned supreme. 1908 to 1912 may he described as a transition period,. in which the relatively Small, high-(0,,iency design gradually ousted the giant from t he field. The 1908 Grand Prix, although still a race of giants,

showed great advances in design, while the T.T. race developed the high-efficiency engine of some 5-litre capacity to hitherto unheard-of outputs. In 1919 the tiny Type 13 B`ugatti (1,200 c.c.) ran second in the Grand Prix (such as it was) to a 10-litre Fiat, and in 1912 a 7.6-litre Peugeot beat a field of 15-litre giants for first place. In the meantime, the Coup de l Auto series of races, which ran from 1910 to 1913, for cars of 3-litre capacity, had been started and high speeds were being attained.

Thus, at the end of 1912, the stage was all set for the next wave, w !tie]) continued from 1913 until 1927. During this period current formulle demanded successively smaller engines, while performance remained fairly constant. Chassis design and case of handling also improved out of recognition. 1928 to 1933 saw a period of desultory ” forint:le-fibre” racing, during. which design advanced but slightly and performance not a lot. Finally, we have the current era, 1934 to 1938, which saw the tremendous advance of streamlining, light alloys and fantastic performance achieved by Mercedes-Benz and AutoUnion.

Design can, therefore, be . fairly well divided into six waves. Unfortunately, no continuous history of racing design has yet been penned, though one is even now unfolding itself before us in the Motor, in the enthralling series entitled ” Milestones of Speed “—a triumph of erudition on the part of the author, Mr. Pomeroy, and hardly less of Mr. Cresswell, whose masterly drawings have combined artistry and accuracy to an extent hitherto almost unknown. When complete, this series must undoubtedly be published in book form-, for it would be a book unique in the bibliography of motoring. Mr. Pomeroy took 1908 as his starting point, for the perfectly sound reason that it was in this year that modern design may be said to have started. The racing machines of 1902 to 1907 had no perceptible influence on what came afterwards. Nevertheless, the picture is not complete without at least a sketch of this extremely romantic period of racing,

and the present article seeks to provide a rapid survey of a necessarily superficial nature. By dividing racing up into these six ” waves ” it becomes much easier to fudge the respective merits of the great drivers clown the years, and this is of some interest because so much ink has recently been spilt on this subject. I suppose it will be conceded that the formative period, un to 1901, produced no great drivers in the modern accepted sense, but the strain on drivers was, nevertheless, very intense, especially before the adoption of wheel steering. Steering gear of those days absorbed no road shocks and any serious bump practically tore the tiller from the driver’s grasp. Wheelbases were generally less than 6 ft. and centres of gravity were

inordinately high. Add to this the delicacy and attention which were necessary to keep the engine in action and it will be seen that to average even 20 m.p.h. over a distance was a considerable feat of skill and endurance. The period from 1908 to 1934 1 should regard as that demanding the least skill from the drivers. The 1008 G.P. machine was eminently controllable, and each succeeding year the ears became easier and easier to control, although but little faster. This leaves the two periods, 1902-1907 and 1934-1938, both of which, interestingly enough, were ushered in by a weight formula : a ton in 1902 and 15 cwt. in 1934. Each was supposed to limit power and performance, and each, paradoxically, instantly evoked an unparalleled increase in both. No one denies that the post-1934 Grand Prix machine calls for skill and judgment such as have never before been demanded of a racing driver, and it is with only a little less force that the same applies to the previous weight-formula ears. Engines of 16-litre and 17-litre capacity were crammed into chassis of the flimsiest proportions with suspension systems fitted for nothing faster than a perambulator. The engines were inflexible, brakes non-existent, tyres narrow and unreliable, roads deco in dust —it was indeed a race of giants that drove the ears. Few names are predominant, but Thery, Szisz and Nazzaro stand out,

while Gabriel’s drive in the ” ParisMadrid ” Of 1903 at 65 m.p.h. average snrnasses the imagination. Pacing proper started with the ParisBordeaux ‘Race in 1895, for the ParisRotten performance of 1894 had not been a race, heft primarily a reliability run. Incidentally, Levassor’s drive in the ” Paris-Bordeafix ” is hardly less reMarkable than Gabriel’s epic, and as a. feat of endurance it cart never have been

surpassed. Driving single handed throughout, he took his 4-h.p. Panhard to victory at an average of 15 m.p.h. for the total distance of 732 miles, having driven continuously for two days and 48 minutes. This, of course, was a car with tiller steering and a maximum speed of 18im.p.h. Going back even further for a moment, it is noteworthy that neither Benz nor DaMtle..r had any direct influence on early racing. Benz was the father of the industry, in that he sold his first car in 1.887 and by 1889 had a factory employing 50 men on the manufacture of motor-cars. But beyond his championing of electric ignition, Benz contributed nothing else to automobile -design. To Daimler we owe the evolution of the vertical, relatively high-speed motor,. and as early as 1883 or 1884 he had attained 900 r.p.m., whereas Benz did not for several years contemplate more than 300 r.p.m. Daimler built an experimental motorcycle in 1885 and an equally crude car in 1886, but he did not start the serious manufacture of cars until some time after Benz. In the meantime, Panhard and Levassor had conic on the scene, and in 1890 they took over the Daimler rights in Paris. It was the early Panhard which first incorporated the essential features of all subsequent design—namely, a vertical engine under a bonnet in front, clash gears and rear differential, with final drive by chain. The 1894 Panhard, which earned such acclamation in the ParisRouen run, had a 15° twin, 75 x14,0, 1,200-c.c. engine, developing h.p. at 730 r.p.m., which is equal to the modest in.e.p. of 39 lb../sq. in. There was no throttle and the engine speed was controlled by a trip gear on the exhaust

valves—a feature which Panhards retained until well past the turn of the century. The carburetter was of the surface variety with a three-way air inlet, controlled at the discretion of the driver, who could thus supply the engine with a normal, super-rich or ultra-weak mixture. Ignition was hot tube and the drive was taken via a double cone clutch, four-speed gearbox (except that there was no actual box and the gears were all exposed) and a single chain to the back axle, which carried the differential. Later models had two chains and a differential on the countershaft. The back axle was always located by radius rods.

The contemporary Peugeot (the only other make of importance in these very early years) adopted a rear-mounted Daimler-Panhard type of engine and a tubular chassis. The racing Panhard for 1895, such as Levassor drove in the Paris-Bordeaux Race, had a basically similar engine to the 1894 car and the capacity was the same, but the bore and stroke were changed to 80 x120. It developed 4 h.p. at 800 r.p.m. and weighed some 182 lb. The compression ratio was 2i to 1 and the pressure in the cylinders was given as 45 lb./sq. in. The carburetter was of the constant-level spray type, in which petrol from a jet impinges on a cone, although it may be noted that Daimler had made a fairly normal jet type carburetter as early as 1889. The gear wheels, of steel and

bronze, were enclosed for the first time in a box and gave speeds of 5, 12i and 18-1, m.p.h. at the engine’s running speed of 800 r.p.m. Some of the other competing Panhards had four forward speeds. The overall weight was 12 cwt. The Panhard double cone clutch was designed for the purpose of taking up the drive more smoothly, the inner cone, which received the power first, being connected to the outer cone by cushioning springs, somewhat reminiscent of those which form part of the modern Borg & Beck clutch.

In 1895 the Comte de Dion first turned his attention to petrol motors, although he continued to manufacture larger steam carriages, and produced his marvellous little tricycle, with a single cylinder, aircooled engine of 140 c.c. (50 x 70). It produced if h.p. and had electric ignition. Later editions had more powerful engines, and in 1897 to 1899 the motor-tricycle was actually faster than the racing cars, although it was so unstable, especially on corners, that the average speeds of the cars were higher. De Dion ran his aircooled engines at remarkably high speeds which were not generally surpassed for another 15 years, and they would attain 3,000 r.p.m., although not for long, as the automatic inlet valves would soon collapse. All cars prior to 1901, and many later, were fitted with automatic inlet valves, operated solely by the suction of the engine.

In 1896 Panhards appeared upon the scene with a four-cylinder motor of 8 h.p„ They still adhered to tiller steering, combined with a wheelbase of 5′ 7″; but in 1897 they and other competitors first began to design cars specifically for racing. The 1897 Panhard had a gilled-tube radiator, and aluminium was introduced for certain components, such as the carburetter, gearbox and lubricators. In the 107.7-mile Paris-Trouville Race the Panhard averaged 25.2 m.p.h. and a Boll& 28.2 m.p.h.

The 1898 Panhard was at last fitted with wheel steering and a four-cylinder 2i-litre engine, 80 x 120. People began to complain about “Special racing giants.” Mors, which was to threaten Panhard supremacy from 1900 onwards, first took the racing field in 1898, with a fourcylinder, 70 x 110, belt-driven machine.

The Panhard motor normally ran at 700 r.p.m., but by cheating with the governor it could be allowed to run up to its “terminal velocity” of 1,200 r.p.m.

Most early books of reference give bores and strokes, but very rarely cubic capacities. To work these out precisely would be an interminable business, and for the purpose of comparison in this article I have only worked to the nearest fifth of a litre. The year 1899 saw a much greater advance in specialised racing car design. Panhards still adhered to their fourcylinder, 2i-1itre motor, but Peugeots appeared with a two-cylinder, 6-litre unit with 140 x190 cylinders. An unsuceessftil freak in this year was the Vallee, with a four-cylinder, 7-litre engine and final drive by a single, 10″ wide, belt I Electric

ignition now gained general approval, though most people still had the hot tube as a stand-by. Mors had a four-cylinder 1 tt-h.p. racer on basieally Panhard lines. Average speeds were up to 37 m.p.h. The year tufa) Nvas the first in which Mon first seriously threatened Panhard

supremacy, itrui they were riteing with a four-cylinder, 119 7 to:5, 7-litre engine, against Panhard’s to I 10, 5-litre ; but the well-tried Panhard was more reliable, and in the 210-ndle Circuit du Sud-Ouest Race de Knyff won at the useful average speed o148.8 m.p.h. on his Panliard, Odell was described as 16 h.p. It had a chassis of wood reinforced with metal plates and the front axle was greatly dropped in the centre—a feature general in racing ears for many years to come. Road wheels were rapidly becoming all the same size and Daimlers appeared with a honeycomb radiator, though the old gilled tube continued to hold the field till as late as 1904. Overall weight was now up to 20 or 24 cwt. on an average. The racing tricycles of 1900 were formidable projectiles with 6 or 8 len. engines, eapahle of 60 m.p.h. in the hands of anyone sufficiently intrepid or skilful, and after 1901 they were discontinued altogether. The year 1901 saw further marked increases in performance and was the last year of “fOrmuledihre•• racing.. Pa nhil increased to 71-fitre engines. 130 110,

and Mors 10-litres, 180 x 105. The Panhard was generally described as ia 40-h.p. machine, equal to 5A h.p. per litre, and the Mors as 60 lip., equivalent to 6 h.p. per litre. In this year was constructed the 13-litre Napier (160 1s5), which covered 5 miles at an average of ’17 m.p.h., but was inq racticable for bugdistance racing owing to tyre greed. It ran at. 1,200 r.p.m., t he speed of the engine being controllable onlv by the spark lever. it was generally considered as the fastest thing awhcel.

Important newcomers in 1901 were Gobron Brittle and Mercedes. The Gobron used opposed pistons. converging upon a central combustion chamber, trie upper piston being connected to the single crankshaft by a beam. This arrangement was calculated to neutralise the thrusts otherwise imposed upon the crankshaft, and also had the merit Of reducing piston sliced. This make was also a pioneer in the use of solid fuel injection, which was effected by ;1 metering pump. The Gobron Willie was a very nice car to drive and raced very consistently het ween 1901 and 190,5, though not w it Ii outstanding success. In 1901 the Daimler firm changed its mune to Nlereedes to avoid anti-German prejudice in t he foreign market, and produced the epoch-making 35-h.p. machine. This was far more advanced than anything else in point of design, though not as yet, in performance. ow lug to its relatively small engine. Nevertheless, it scored a win in the Paris-Niee Race at 30 m.p.h. Novel features included a Pressed-steel frame, honeycomb radiator, mechanically operated inlet valves and

gate change. Final drive was by Chain. This was the first fairly large engine to combine genuine flexibility and silence with performance, and the general appearance of the car was also some years ahead of’ its Oraand distinctly handsome.

Average weight in 1901 was up to 28 cwt. and the highest winning speed was returned by Fournier, on a Mors, in the Paris•-Bordeaux Race, which he won at 53 m.p.h. The year 1902 was the first Of formula racing, weight being limited to 1,000 kilogrammes or 1.007 for cars fitted with magneto ignition. This is equivalent to about one ton. As an attempt to limit perfOrimmee this formula was as great a frost as the 750 kg. formula of 1931 for whereas the 1901 Panhard had weighed some 25 cwt. and developed 40 h.p., the 1902 machine developed 70 h.p. within the prescribed limit of a ton ! Not every manufacturer, however, went all out for power ; Mors concentrated more on

staying power and Mercedes pinned their hope almost entirely on reliability.

The Panhard had an armoured wood frame and a transverse front spring with tun fer,:lmeg shackles and a very light axle. The springs possessed only four leaves, each 75 nuu, thick, and were undamped ; they were not really strong enough to nico I heir commitments. There is no evidence of the Panhard rod ” now a good deal spoken of in connection with trans?,-erse springs. The engine was bolted direct to the frame, instead of being carried in a subframe, as previously, and had a capacity of 13i litres (160 x170). It 70 h.p. it will be seen that the power per litre of his larger c11.2:ille Was less than the 71-litre engine of 1901. In the interests of lightness each cylinder was separately east and surrounded by a 1 mm. thick copper water jacket, brazed on, and corrugated to allow for expansion and contraction. The inlet valves were three

port, automatic, with a total diameter of 130 mm. and a lift of 4 mm. The three valves were contained In a single detachable cage. The multi-tubular radiator had nine rows of 20 tubes each. Ignition was by four separate coils ; lubrication was splash ; the steering had no castor action. The Panhard was, in fact, an out-rnoded design, relying on brute force, as it continued to do with decreasing success until its disappearance from racing after 1908. Nevertheless, a Panhard won the ParisBelfort Race at the respectable speed of 54.4 m.p.h. The Mors carried a 9.2-litre, 140 X150 motor, with direct drive on top and a dog-clutch device for locking the cone clutch at will. Despite its fairly small engine, the Mors was very fast and was tinted over a flying kilometre at 77 m.p.11. It was the first car to be fitted with shock-absorbers, carrying two on the front axle and four on the back. These shockabsorbers were of dashpot pattern and

exerted a notable influence upon the Stability of the cars. Mercedes had an even smaller engine,

of only 6.8 litres (120 /, 150). The cylinders were ‘cast in pairs with the heads and water jackets integral. As before, all valves Were mechanically operated and disposed in a ” ” head. The axles were steel tubes, ignition was by low-tension magneto, the clutch was of the Mercedes coil variety, which was very nice as long as it was ” just so.” Four brakes were provided, all operating on the rear wheels, and water-cooled. An interesting, but not very successful, model of 1902 was the eight-cylinder,

125 x130, Dufaux, which also had chrome-nickel axles. Underslinging made its first appearance in the very low built Wolseley ” beetles,” which had horizontally opposed four-cylinder engines. An interesting thing happened in the Paris-Vienna B ace of 1902 when a Renault (100 X120, 3.85 litres), running in the

Voiturette Class, had the indecency to come home in front of all the “Real Racers,” at an average speed of 38.9 m.p.h. This was, indeed, a flash in the pan, but, nevertheless, a forewarning of the eventual supremacy of quite small machines over the giants, some 10 years later. The Renault was interesting as having shaft drive, but it was not until after some years that most manufacturers were willing to transmit much power through a live axle, Renault being the pioneer champions of this form of drive.

Compared with the great advances of 1902, the designs of 1903, 1904, 1905 and 1906, the remaining years of the 1,007 kg. formula, are not so revolutionary or generally interesting.

The year 1903 is principally remarkable for the fatal Paris-Madrid Race, which put an end to the long, inter-town races. In it. there were two epic drives—that by Gabriel, the winner, on a Mors, at the tremendous speed of 65.3 m.p.h., and, no less remarkable, that of Louis Renault, who won the Voiturette Class and was second on general classification at 62.3 m.p.h. The Voiturette Class had a 650 kg. (about 13 cwt.) limit and the Renault was described as 30 h.p. Panhard’s at last adopted the pressedsteel frame and had a five-bearing engine (which made it possible to employ a lighter crankshaft), slightly canted in the frame so as to give the flywheel more clearance. For the first time, too, their inlet valves were mechanically operated and the cylinders had ” T ” heads. The connecting rods and pistons were drilled for lightness. The engine was 13f-litres (160 x 170), and a strange feature of design lay in the three-speed gearbox, of which the back end was on the countershaft and the front end was hung from the sub-frame by rods and coil springs. The engine of the 70-h.p. type weighed only 680 lb. and ran at 950 r.p.m. The pistons in the racing engines were slightly domed and very long. For front suspen

sion the makers had reverted to semielliptic springs. The carburetter was a Krebs, variable choke type, working against a spring tension. The year 1903 saw the last appearance of the valiant Chevalier Rene. de Knyff at

the wheel of a racing car ; for eight years he had been the almost undisluted doyen of motor racing. Mercedes had found it necessary to increase power, though their just mechani cal scruples clearly found them ill-at-ease with the weight formula, and it was not until after its removal that they really came into their own, in 1908. Their 60-h.p. machine was a 9.2-litre (140 x 150), running up to 1,000 r.p.m., with the familiar scroll clutch. The carburetter was a multi-jet device. The inlet valves were now overhead, in the centre of the head, and of annular type, which, with valves of very large diameter, increases their effective opening area without resorting to an excessively high lift. The

tubular axles of 1902 had given way to conventional ” I ” section. Even by modern standards, the touring edition of this model is genuinely flexible and silent, and a pleasure to drive.

Mors turned out with 11f litres under the bonnet (145 x 175), and the little Renault, so phenomenally successful in the Paris-Madrid Race, had a 61-litre (124 x 130) engine.

An important event in 1903, though not directly connected with racing, was the first appearance of a successful production six-cylinder motor-car, Napier’s marketing such a machine of some 41-litre capacity, which made an altogether new record in silence and flexibility. Yet another important British innovation was the Maud.sley, which was the first production car to possess an overhead camshaft. Generally speaking, the springs and frames of 1903 were stronger than in 1902, though, of course, they were still very

,flexible. Piston speeds ranged from 700-1,000 It per minute. The cars were now pretty fast and the speeds evidently created a powerful impression upon beholders, as witness the following exquisite outpouring by a writer in the Autocar in 1903, after seeing C. S. Rolls traverse a flying kilometre at a little over 80 m.p.h. :—” Hurling the air to each side, so that it struck the face like whiplash, the car tore past in one blinding flash, while the car was rent by the shriek of the driven demons within. The car seemed veritably to spurn the road behind it as it came on with steering wheels lashing under it, as though the myriad strokes of its engine maddened it to mighty leaps.” In 1904 the Richard Brazier came into the picture and Thery steered one to

victory in the Gordon-Bennett at 54.5 m.p.h. The engine was a 10-litre (150x 140), running at some 1,200 r.p.m. 1 he chassis Was fitted with shock absorbers. The increasingly archaic Panhard scored its last wins of importance in the hands of Heath, at Ardennes, and in the Vanderbilt Cup. In 1905 the best he could manage was two seconds. It now carried an immense engine, 170 x 170, whose 15 litres were accredited with an output Of 90 h.p. To squeeze such an enormous power unit into a vehicle weighing no more than a ton was a truly remarkable feat, especially when aluminium was the only light metal available ; yet we were all quite astonished, 23 years later, that AutoUnions, by extensive use of light alloys, were able to power their 15-cwt. racers with 6-litre engines.

Mercedes had 12-litre (195 x 140) engines and deserved better than they fared. They still used rubber Snubbers instead of real. shock-absorbera.

In this year Dufaux scored a record in bores, with a machine which was apparently intended for sprints. This time it was a four-cylinder, with the immense bore of 225 mm. A stroke of 166 gave a capacity of 261r litres. Chrome-nickel axles were again used. This engine comes close to the four-cylinder record capacity of the 1911 300-11.p. Fiat, which was 28A litres, given by 190 X 250 cylinders.

In this year a Darracq traversed a flying kilometre at 104 m.p.h.

The year 1905 saw very diverse engine capacities, some manufacturers still pinning their faith on huge engines and others realising that tyres were the limiting factor, so that smaller engines were likely to succeed. Both schools of thought met with Some measure of success. The Gordon-Bennett Race of this year was over a very twisty course, and to improve cornering stability Renaults had introduced an underslung chassis with a 13i-litre (166 x Ili()) engine. By contrast, the de Dietrich had a monster engine of 17 litres (190 x150), and Ralas won the Brescia Race on a machine of the same capacity and 185 x 155 cylinders. This car, w hich is still in existence, is one of the most imposing spectacles imaginable. The cylinders are in two blocks and have overhead inlet valves. Ignition is by lowtension magneto. It also has shaft drive, which is remarkable with so large an engine at so early a date. ‘Fite carburetter has a.spring tension, variable choke device and, in general, the design is remarkably similar to the 1908 Grand Prix Machine.

The Richard Brazier which won the Gordon-Bennett Race had a 10?,–litre, side valve, 160 x 140 engine, with the cylinders cast in pairs, and an L.T. magneto. Darraccfs also realised the advantage of a moderate engine capacity, being content with 10 litres (150 x 140), while in the light car class they provided their quite successful machine with a solid rear axle. The standard of design had advanced most noticeably in 1905 and the ability of Italian engineers first came to the fore. Besides the excellent Itala, the Fiat was undoubtedly the car of the year, having a 16-litre (180 x 160) engine, with pushrod operated valves, inclined in the head, at an angle of 00 to each other. Fiats were brilliantly driven hy Laneia during

this year and be was robbed of victory by exceptional bad luck on two occasions. Another car with inclined valves was the Pipe, which had dual ignition, by coil and magneto.

The year 1906 was more than ever governed by tyres, for speeds had increased considerably. Renault, Fiat and Itala gained a marked advantage by the use of detachable rims ; several other competitors, such as Panhard, would have liked to use them, but were unable to do so without exceeding the 1,007-kg. weight limit. The Grand Prix, at Le Mans, was an exceptionally hard one for men, machines and tyres, and Szisz won at an average speed of 63 m.p.h. for the 770 miles—a fine performance. Generally speaking, racing during 1906 was someWhat desultory and lacking in competition, for the weight formula had now quite outstayed its welcome, but there were a few interesting designs, nevertheless.

Mercedes were experimenting with a six-cylinder o.h.c. engine, but relied mainly on the four-cylinder push-rod engine as the first line of defence. Piston speeds had risen in some cases to nearly 1,500 f.p.m., notably in the long-stroke Clement-Bayard.

Experiments had started on front-wheel brakes, although it was some years later that Argyll and Isotta Fraschini put them on the market and not until 1914 that. they appeared in racing.

F.I.A.T.’s produced a most interesting 101-litre Machine, not primarily a racer, with a bore and stroke of 145 x165, whose crankshaft revolved at the remarkable speed of 1,800 r.p.m., giving a piston speed Of More than 1,900 f.p.m.

The best of the Grand Prix machines were now capable of better than 90 m.p.h., while Marriott, on a Stanley Steamer, had covered a flying kilometre at 121.52 m.p.h.

The Americans had been making interesting experiments with multi-cylinder engines of various shapes and sizes, and also air-cooling, but their products never really came into the class of European Grand Prix performance. The following table gives a certain amount of data about four of the most interesting Grand Prix machines of 1906. The b.h.p. claimed for the Bayard is probably optimistic :—

Tourist Trophy racing was beginning to become interesting and the is inning Rolls Royce had a 4-litre (101 x 127) engine, giving 22 h.p. at 1,000 r.p.m., which is only equal to 70 m.e.p. It had an 8′ 10″ wheelbase, dual ignition and gear ratios of 6.4, 3.85, 2.65 and 1.89 to 1, direct drive being on third gear. For 1907 Germany proposed a minimum weight limit of 1,175 kg. (about 23 ewt.) and a maximum engine capacity of 8 litres, and had their suggestion been adopted racing design might have advaneed very much faster during the following six years than it actually did. The Grand Prix formula actually adopted worked on a fuel consumption basis equivalent to 9.4 m.p.g. Other races, however, adopted different fornitihr,

must have been very confusing and expensive for manufacturers, who, notwithstanding, turned up in force for every race. The Targa Florio had a rather tiresome maximum bore and minimum weight formula, which failed to produce very interesting results, but for the Kaiserpreis Race the Germansimposed the regulations which they had suggested for the Grand Prix. They also stipulated .a minimum wheelbase of 9′ 101″.

The Grand Prix was held at Dieppe and a Fiat came home in first place at 79.5 m.p.h., driven by Nazzaro. It had a 161-litre (180 x160) engine, and he had enough petrol left over at the end of the race to cover another 30 miles. For such a huge machine to average better than 9i m.p.g. under racing conditions is really remarkable. Stisz was a close .second on a Renault at 69.4 m.p.h., with a much smaller engine of 13 litres (166 x 150). As he had more than 20 gallons to spare it Would seem that he might have won had be pushed along rather more eagerly. There was also a Voiturette Class in the Grand Prix, the cars being invited to average 18.8 m.p.g. The winner was a 5flitre (120 x120) Darracq, at 55 m.p.h.

In the Brescia Race, Cagno won on a 15/-litre (175 x155) Haiti, at 65.2 m.p.h. and a fuel consmnptiou of exactly 10 m.p.g. The Kaiserpreis Race produced a most interesting crop of entries, and the capacity limit began to Make people think carefully about the most advan

tageous bore-stroke ratios. Generally speaking, 140 x130 was a favourite arrangement, but Mors had a six-cylinder, 114 x 130 engine. Fiat and Pipe ran first and second, and both had hemispherical heads with inclined valves. But far the most instructive race of the year was the Circuit des Ardennes, in which both Kaiserpreis and G.P. cars competed on comparable terms, to the marked advantage of the former. The event was a runaway for Minervas, who took first, second, third and sixth places, although they had not performed -with any distinct ion in the Kaiserpreis event— evidently the interval of time had permitted the snags to be overcome. The actual winner was Moore-Brabazon. The fastest (LP. car was a Mercedes, which averaged 57.3 m.p.h., as against MooreBrabazon ‘s 59.5 m.p.h. 1-having regard

to this, it is remarkable that 12 and 15litre machines continued to appear in Grand Prix racing until 1912. The overall weights of the Grand Prix and Kaiserpreis machines were almost identical, so that there was no advantage held by the Kaiserpreis cars even on that score.

The year 1907 was indeed very instructive and successful, and with it this survey might really stop, since the Motor series commences with 1908. Nevertheless, as 1909, 1910 and 1911 produced no serious Grand Prix racing, it seems worth extending the present article to the end of 1908, as marking the end of a great series.

For 1908 Germany had proposed a maximum bore restriction of 135 mm. for four-cylinder cars, but the figure eventually decided upon was 155 mm., with a minimum weight of 1,100 kg., equal to about 22 cwt.

‘1 he limitation upon bore naturally turned designers’ attention to the best means of increasing power in other ways. Obviously, increased stroke and r.p.m. were the answer, and so piston speeds went up with a jump ; 155 x 1CO3 giving 12-litre capacity, was a usual figure, but Mercedes used both 155 x170 and 155 x180, the latter giving 13* litres. The largest car was the Clement-Bayard, with 14f litres (155 x 185). It normally ran at 1,566 r.p.m., giving a piston speed of 1,900 f.p.m., but a usual figure was nearer 1,750 f.p.m. ; b.h.p. was not generally divulged, but Lorraine Dietrich, with a Li-litre (155 x 175) engine, was commonly accredited with 123 h.p., the Mercedes with 120 11.p. and the ltala with 115 h.p. ‘Nr ith the increase in r.p.m., mean effective pressures were lower than in OM, 75 being a general figure, although, of course, power per litre was substantially up, averaging 9 to 91, as against 8. to 9 in 1906.

Many cars now had inclined valves, but Rala adhered to inlet over exhaust, combined with a hemispherical head and low-tension magneto ignition. Panhard’s and one or two others still retained the old ” ” head, with steel cylinders and copper water jackets. ltala had a threebearing crankshaft with mechanical feed to the main bearings and splash to the big-ends ; the bearings were a very soft species of white metal. The extra piston speed raised all sorts of cooling and oiling problems, and the cars were freely luuricated in all directions. Cylinder head and valve seat cooling also received far greater attention than previously. Metallurgy also began to come to the fore as a factor in design, and the quality of the available steels was much improved. Gear ratios were generally closer than before, those of ltala being 1.8, 2.3, 2.8 and 5.3 to 1.

Most of the cars came fairly close to the minimum weight of 1,100 kg., but the otherwise excellent Ralas burdened themselves quite needlessly with an overall weight of more than 1,400 kg.–an extra 6 cwt. above par.

Napier’s entered a most interesting and effective looking six cylinder machine, winch, however, was excluded by the organisers on the totally unreasonable grounds that it had detachable wire wheels and was therefore unsafe. In the Grand Prix tyres were once more the limiting factor, for 100 m.p.h. was commonly attained on the level and as much as 120 m.p.h. was mentioned on the downhill stretches. Lautensehlager won the race on a Mercedes

at an average of 69 m.p.h. and probably owed his victory as much as anything to nursing his tyres on the corners. One of the Mercedes team cars still exists, in excellent condition, in America. The Voiturette Class in the Grand Prix permitted cars of one, two, three or four cylinders, with maximum bores of 100, 78, 68 and 62 mm., respectively, and a Minim uni weight of 600 or some

of 600 kg., or some 12 cwt. This formula, unfortunately, ignored the higher frictional losses of the four-cylinder engine of such dimensions, so that the really more retrograde singles had the advantage, and the event was won at the useful speed of 50 m.p.h. by a 1.2-litre (100 …150) Deluge. This car had six-volt ignition and no lewer than four sparking plugs. It also had two flywheels. It was estimated to evolve 1:4 b.h.p. at 1,977 r.p.m., giving a mean effective pressure of 85 lb./sq. in. Sizaire Naudins also had a single cylinder with both automatic and mechanically operated inlet valves, the speed of the engine being controlled by varying the lift of the mechanical inlet valve. They also had an effective system of front independent suspension by transverse leaf spring ; 2,000 f.p.m. was an average piston speed, but the Gregoire and Alagon went. to 2,213 f.p.m. The highest crankshaft speed was attained by the four-cylinder, 1,000c.c., 62 x 84 Martini, which exercised itself at no less than 3,300 r.p.m. and developed an estimated 16 b.h.p., equivalent to an m.e.p. of 05. The piston speed at 3,300 r.p.m. was the quite modest one of 1,850 f.p.m., and altogether the Martini must have been a most advanced, interesting and commendable little machine. The greatest freak of the Voiturette Class was the Corre-la-Lieorne, which had a 2.2-litre single-cylinder engine with a stroke of no less than 300 nun., and the record bore-stroke ratio of 3 to 1.

From the point of view of improving design, the 1908 T.T. Race was even more interesting than the Grand Prix and Coup des Voiturettes. The formula stipulated a minimum weight of 141 cwt. and a maximum bore of 4 in. (100 mm.). Even more than in the Grand Prix did this stress the importance of putting up piston speeds, and designers also found that a long stroke was a useful means of raising the compression ratio without resorting to awkward-shaped combustion chambers. The winning car was a s.v. Hutton of 6i-litre capacity (4″ x 8″ and, therefore, over 200 mm. stroke), which ran up to

2,000 r.p.m., giving a piston speed of 2,700 f.p.m.—a great advance over the G.P. m ael i nes ; 70 b.h.p. was claimed for it, equal to nearly 11 per litre and 70 in.c.p. The most successful team as a whole was Darracq, who used a 160 mm.

stroke, giving a capacity of 5.2 litres. These ears cruised at 1,000 r.p.m., giving a piston speed of 1,050 f.p.m. One of the Hutton team exists to-day and, although it looks a most agricultural machine compared to the 1908 G.P. cars, it is certain that a great deal of care and expense went into its preparation and that it well deserved its win. Compression ratios in the order of 4i to 1 were current.

After 1908 the T.T. was dropped until its re-appearance in 1914, and light car development was carried on during the intervening years in the French, 3-litre maximum, Coup de l’Auto races, which deserve a special article to themselves.

Curiously enough, even higher engine efficiencies were being obtained in 1908, in the more advanced cars entered for the 2,000-mile R.A.C. Reliability Trial, outstanding being the 3-litre Vauxhalls, which ran up to 2,500 r.p.m., at which they developed at first 40 and later 52 h.p., equal to no less than 17 per litre and the quite modern m.e.p. of 88 lb./sq. in. The year 1908 was, in fact, a bumper one, and it is curious that it should have been followed by a period of such relative stagnation. And so closes an epic period of motor racing—not to mention this apparently interminable article