SELDOlvl in the history of the land speed record has so exciting a duel been waged as that which took place in Utah last month between Capt. G. E. T. Eyston and J. R. Cobb. Apart from the honour of holding the record itself-or rather, the record for the mile or kilometre, whichever happened to be the faster-there were two "landmarks " to be reached, 350 m.p.h. and six miles a minute, or 860 m.p.h.

Whereas George Eyston secured the major honour of bringing back to England the record, now standing at 357.5 m.p.h. for the flying mile, and on one run failed to achieve six miles a minute by only .4 m.p.h., John Cobb's was the distinction of being the first man to reach 350 rn.p.h. on land.

The first round in the duel, when Eyston raised his own record of 312 m.p.h. to 345.5 m.p.h. for the mile (mean time 10.42 secs.) and 345.2 m.p.h. for the kilometre (mean time 6.48 secs.) was reported in last month's issue of MOTOR SPORT. The full times and speeds for the latest attempts by the two drivers are as under. John Cobb made his attempt first, with the four-wheel-drive Railton, on September 15th :

Eyston had gained another 12 m.p.h. since his first attempt this year by several

modifications to "Thunderbolt." The most important of these was the removal of the radiator and the substitution of ice-tank cooling, a big change to carry out in the short space of three weeks. Eyston, however, is not only a great driver but a very capable designer and practical engineer as well. The merit of this system of cooling, which could only be used for these short distance records, is that it enables a smooth unbroken nose to be used for the car, without the air disturbance caused by wind rushing through the radiator. John Cobb's Railton was already fitted with ice-tank cooling. The first driver to adopt it was the late Frank Lockhart,

the American, for his black Hawk Stutz, with which he attacked the land speed record at Daytona in 1928.

This remarkable car had a sixteencylinder 3-litre supercharged engine, and weighed. only a little over a ton. It may thus be regarded as a direct predecessor of the modern formula cars, especially as Lockhart actually attained 202 m.p.h. on one run-ten years ago ! Lockhart never broke the land speed record, as he met with a fatal accident at Daytona beach, but the 1i-litre record of 164.01 m.p.h., which he set up in 1927 over the flying mile on the dry lake bed at Muroc, driving a Miller, still stands.

Another modification to " Thunderbolt " was the removal of the tail-fin. This is interesting, as George Eyston has hitherto been of the opinion that a tailfin is of some value in securing directional stability at these very high speeds. The original 200 m.p.h. Sunbeam driven by the late Sir Henry Segrave had no tailfin, but the big car got into several terrifying swerves, and it was thought that a fin, similar to the rudder-plane of an aeroplane, would help to keep a car straight.

Until the recent record attempts, all subsequent machines have had a fm, with the exception of Lockhart's Stutz and the crude three-engined Triplex, which, though it broke the record in 1928 at 207.552 m.p.h.., driven by Ray Keech, had practically no body at all.

Cobb's Railton, with its exceptionally smooth body, the only excrescences on which are the cover for the driver's cockpit and the shields over the wheels, is not fitted with a fin. As long ago as 1933 Reid Railton, designer of this machine, stated in an article in a technical paper that he doubted the value of a tail-fin. In spite of this, he retained it on Sir Malcolm Campbell's series of " Blue Birds," for the general design of which Railton was responsible from 1931 onwards, though in " Blue Bird's" latest reconstruction, when in 1935 Sir Malcolm attained first 276.82 m.p.h. at Daytona and then 301.13 m.p.h. on the Salt Flats, the fin was much abbreviated. Now it seems probable that the fin, which has even been fitted on various pseudo-sports cars, will disappear from

the giant record-breakers. It not only constitutes additional weight, but tends to upset the flow of air round the streamlining of the tail. The matter of weight is not so unimportant as one might imagine, considering the massive construction and huge engine power of these big machines. " Thunderbolt " weighs about six tons, and the Railton only a little over half that

amount. However, owing to the fact that Eyston's car has eight wheels, and Cobb's the normal four, the former machine has actually less weight resting on each tyre than the latter. Thus, after Cobb had left, it was actually possible for Eyston, on a final experimental run, to make use of some of the

tyres which his rival had left behind, as the supply was running short. No further record resulted, as part of the body broke away and became entangled with the rear wheels, damaging the rear suspension and other parts of the car. " Thunderbolt " was travelling at full speed at the time, and Eyston had a lucky escape from disaster. With George Eyston not yet home from the U.S.A. at the time of writing, speculation as to his future plans is

fruitless. " Thunderbolt " has now travelled at over 300 m.p.h. fourteen times, including various trial runs, and it is thought that for his next attempt Eyston will either entirely reconstruct the machine, or build a new car. Cobb has also announced his intention of making a further attempt next year, and after the success of the four-wheel-drive fitted to the Railton, it seems likely that this form of transmission will at last come into its own.

When Sir Malcolm Campbell raised the record to 300 m.p.h., he announced he would make no further attempts unless the land speed record was threatened by a foreign driver. Eyston and Cobb have rendered this possibility sufficiently remote, and Sir Malcolm has been pursuing his endeavours to make the water speed record equally safe.

Just as interest in the land speed record really became general when Segrave first attained his epic 200 m.p.h., so it was the same driver who focused attention on water speed by his duel with Gar Wood, in which, at the very moment of his tragic accident at Lake 'Windermere in 1930, he emerged victorious.

Gar Wood subsequently found Kaye Don a serious competitor, but in 1932 the veteran American pilot established a new record at 124.86 m.p.h.

This record stood until Sir Malcolm Campbell entered the lists, and last year recaptured the honour for Great Britain with a speed of 129.5 m.p.h. Thus for a brief period he held the fastest speeds ever recorded both on land and water, a joint distinction which he shares only with Sir Henry Segrave.

Now, by a curious coincidence, on the day following Eyston's new land speed record-though Sir Malcolm had been trying to set up new figures with his speedboat " Blue Bird" for some considerable period and at different venues-Sir Malcolm, at Lake Hallwil, in Switzerland, has raised the water speed record to 130.91 m.p.h.

In car records it is only the time that counts, and no definite margin of speed is necessary. On water, however, a speed has to be multiplied by 1.0075 before a record can be claimed. On the day of Sir Malcolm's successful attempt, in an earlier run he had recorded 129.72 m.p.h., which just failed to beat his own previous figure by a sufficient margin. His next run, however, gave him the water speed record, and thus on. one element he is still supreme.