IThe late J. G. Parry-Thomas, who was killed while attempting to raise his own " Land Speed Record " at Pendine Sands in 1927, is still remembered as one of the most famous and picturesque figures that the Sport has produced. One of his greatest achievements was taking the Brooklands Lap Record in 1925 at 129.36 m.p.h. with the Leyland-Thomas. At the outbreak of war this record stood only 14.08 m.p.h. higher—and it took a car of three times the Leyland's capacity, emanating from the works Thomas founded, ten years to raise it this amount. We have long wanted to publish the life history of the great driver-designer. Now, thanks to F. Sumner, A.M.I.A.E., who, after his discharge from the Army in 1916, worked with Thomas during the rest of the last war, and to Mr. A. F. Chief it is to do so. We know that what Saunders, who was associated with Thomas later as his Chief Draughtsman, it is possible to do so. We know that what these gentlemen, both of whom are very fully occupied on tank-design, have contributed will be read with keen interest by our readers, whether or not they saw " J.G.P.-T." in action.—Ed.1 Mit. SI.AINF:11 writ,..s • ••I have been asked by the Actin!, 1,:ditor of MoTon Spoirr to write s(anething on the life of the late J. G. ParryThomas for the benefit of its many readers who are admirers of the contributions this great. designer and rat ing driver nunli to motor-raring. Actually, I know very little of Thomas's career, so 1 have asked a colleague of mine, who was in his employ until his onlortunitte death and who spent years with him. to continue the story where I leave off. NS hieh he has

kindly consented to do. I was with Parry-Thomas only during that. period which must have led him up to the epreer of racing motorist. " Prior to the 1914-18 war, Thomas was an electrical engineer and he devoted a great deal of his talent to petrol-electric trains and trams, designing the latter, for instance, in 1910 for Morecambe Corporation. It was in this capacity that he made contact with Leyland Motors, Ltd. This firm had. made a number of rail-cars of his design and sold them to South Africa. This contract was maintained right up to 1914, when a lot of this work had to be dropped in favour of important war work. Soon after war broke out Parry-Thomas was co-opted as a member of the NIunitions Inventions Board, an office he held throughout the war. In 1915, along with other well-known motor firms, the Leyland Company commenced designing aero-engines. Their engine was an eighteen-cylinder job of about 450 ILI>. Parry-Thomas was persuaded to take over this new branch of the Company, and it was soon evident that he had his own opinions as to what aero-engine design should be like. Instead of carrying on with the eighteen-cylinder engine he produced one of his own layout. It was an eight-cylinder water-cooled radial, in the form of a Maltese cross. Thomas must. have realised, even in those days, the importance of low frontal area. The cylinders were arranged in pairs from front to rear and the two era nkpins were in the same phase to prevent a rocking couple from end (.11(1. Each crankpin carried one inastcr connecting rod and three articulated rods. It was it reneirk ably compact engine with an extremely good ratio of total weight to horse-power. It was something in the neighbourhood of 1i against the previous lowest of about 3 lb.b imp. As was to be expected, the engine bristled with !level ideas. Oil was pressure-fed through the hollow crankshaft to the hearings and a built-up water pipe in the crank shaft cooled the oil as it. passed through the crankshaft. The valve springs were Of leaf-type, with slots at each end of the main leaves for engagement with the adjusting screws on the valve stems. These screws were in the form of a screw

in two parts, with one section of thread slightly out or step with the other, providing a locking device that was quite unique at that time. When screwed down, tme part locked itself' tightly on the valve stem, the cams operating directly on the screw. I believe Chrysler usc a similar means of locking their tappets at the present time. The crankcase was of a special aluminium-alloy and the cylinders likewise, with wet liners. The bottom part of each cylinder liner was unjacketed and subjected to air delivered from a duct round the crankcase. The cranksh:‘It ran directly in the crankcase, there being no white metal. whatever. The linal reduction to the propeller v, as through bevel rears, arranged very similarly to those in a car's differential, and giving a ratio of 2 to 1, the propeller thus being directly in line with the crankshaft. A Constantineseo gun-gear was incorporated, and the equipment actiedly included an electric self-starter and a generator.

" On the completion of the design, experimental work was commenced on a single-cylinder test rig. It was about this time that Mr. Reid Railton, now world famous in the sphere of high-speed car design, came to join our staff, if 1 remember rightly, straight from the University. He was not destined to stay long, as he shortly aftercsards started a brief career in the 11

" During this research period Railton and I put in Many long days and nights testing the single-cylinder version of the Thomas aero-engine, and when he left for the Navy the whole of the responsibility of test imig and of the collection or data was entirely in my hands. I was with Thomas continually until this work concluded. " Parry-Thomas was very exacting in his testing and research work. All manner of apparatus had to be devised at his command for testing various components, such as sparking plugs, magnetos, carburetters, etc., whilst special apparatus was also rigged up to test the speed of air through the valves, the efficiency of the propeller reduction gears, and so on. All this work was carried on unceasingly day and night, snatching a few hours' sleep when we could. At the same time, 'Thomas had to attend meetings of the Munitions Inventions Board, visit the Air Ministry and Admiralty, etc. He travelled at night, so as to get a little sleep. When he was satisfied that the single-cylinder unit had reached its peak of power development and crankshaft speed, the full-scale prototype engine was built. The first trials were made just before the Armistice of November, 1918, and were something of a disappointment. To reduce weight to a minimum, Thomas had skimped the crankcase design and after a few hours' running this collapsed completely. With the Armistice the engine was abandoned ; had it been lin weeded with it would, I think, have been a big step forward in aero-engine design," [As it was, Thomas preceded the DaimlerBenz engineers in the adoption of this cylinder layout by some 25 years.--Ed.] "Time experience gained in developing the aero-engine was not wasted, for Thomas soon commenced the design of the Ieyland straight-eight car, embodying in its engine a number of features of the micro-engine. This car was about ten years in advance of anything made at that time." [Probably it was more advanced amongst unfreakish designs than any car before or since. A description and roadtest report appeared in MOTOR SPORT in

February, 1938.---Ed..1 "It was a remarkable car and I know all the staff enjoyed ‘1,4,rking on it. "To conclude this stage of Thomas's career I would like to recall that when he joined Leyland's in 1916 I do not think he c ould drive a car. My father tells of often taking him out on 6-ton lorries to give him driving experience. Thomas later bought an old Fafnir to get around in which was only capable of tfotit 30 m.p.h. When be first drove a Leyland straight-eight he took to high speed as a duck takes to water ; everyone predicted a short life and a merry one ! On one occasion when he and the Managing Director went to London in one of these ears, Thomas wagered that he could leave Euston at. the same time as the North-bound express and he in Preston before the train, a journey of about 212 miles by Mad. And he did It. was a remarkable piece of driving in a ridard car, and it was possibly this I'cat which decided Parry-Thomas to take up motor-racing after he left the Leyland Company.'' [As 1.11r. Saunders's " copy" was not to hand at the time of going to press this article will be continued.]