IT is an interesting speculation as to where progress in regard to speed will finally lead us. A few years ago the world’s fastest land speed was 170 mp.h., attained by cars of colossal engine-size which were totally unsuited to road-work. The 1934 Grand Prix cars can attain this speed as a matter of course in a race like the Tripoli G.P.

It is less than five years ago that the 750 c.c. speed record was about 90 m.p.h. Nowadays this speed is within the reach of the owner of a 750 c.c. sports car which can be tuned to the requisite pitch of efficiency, and the record has gone up to close on 130 m.p.h.

Where is it all likely to end ? One things is certain ; speeds will increase. It is easy to think, after some particularly fine achievement, that a limit has been reached in design and human ingenuity, but records are made to be broken.

Sir Malcolm Campbell is already planning an attempt on his own 272 m.p.h. world’s record, and one cannot conceive of his returning from America without having exceeded this figure. Yet when he did 272 m.p.h. at Daytona last year, one instinctively felt that land speed could not go higher. In the matter of road racing cars the problem is a more complicated one, for more factors have to be taken into consideration. Cars cannot be above a certain weight, so that power-development has to be carried to

its uttermost limits. The low weight and terrific speeds demand perfect weight distribution, and cornering attributes must be studied closely. Then brakes are subject to far higher stresses than ever before, and here again, weight distribution plays its part, as it also does in regard to steering.

Finally tyres. For straightaway records the problem, although extremely intricate, is free from the complications of braking and cornering stresses, but it looks as though the 180 m.p.h. road racing car will prove a difficult task for tyre designers. But so often have they overcome their jobs in the past that they will inevitably triumph over this new one.

The effect of all this on private cars is evident to anyone studying modern automobiles. Engines are faster and more reliable, brakes are better, streamlining is being carried out, principally in Germany and the U.S.A.

What will the racing car of the future be like ? For touring car design follows in many respects. Of 1934 examples the Auto Union is the most revolutionary with its engine at the rear and independent springing But for cornering abilities on a winding circuit it has yet to be proved, although for speed it is certainly not lacking.

For a real comparison of progress, compare the Auto Union of 1934 with the land speed record holders of ten years ago.