speed and weight. What I mean is, that springing which has done well on an extremely light racing car, at high speeds, is very much akin to that which is suitable for a heavier car which is not called upon to do such high speeds. On Brooklands we learn the alphabet of suspension.

“Small modifications in tyres, too, which we have found to be desirable for track purposes, modifications introduced by the makers at our request, to improve the reliability and safety of the tyres, are, after a time, incorporated in the general run of tyres as turned out by the manufacturers for ordinary use, so that we, the manufacturers of cars, who use the track on which to perfect our products, are helping the general run of motorists in that way.

“A typical example of the direct influence which racing has on the design and construction of cars which are sold to the general public occurred at about the time we determined to secure the roo miles record for A.C. cars. We fitted an overhead six-cylinder engine with four valves per cylinder, but could not keep the valves tight. Time after time a car would lose its power after a short spell of running, and the loss would be traced to leaky valves. No matter how carefully those valves were ground in, trouble would as surely develop. The self-centreing valve was invented, and applied, with almost miraculous results. A car would come off the track, after a hundred miles of running, at recordbreaking speeds, and its valves would still be as tight as before. These valves, which hardly ever need grinding in, are now standard on overhead-valve six-cylinder engines, to the considerable benefit of the user.”

On the relative merits of road and track racing, Mr. Edge holds decided views. He thinks, however, that we should be allowed to hold road races in this country.

“Many members of the public,” he said, “hold the opinion, quite wrongly, that a road race is a more strenuous trial of a chassis of a car than one run on Brooklands. There is nothing in road racing to justify that view. The only stress brought about by road racing which is not actually encountered with greater intensity on the track, is that due to cornering. People have the same idea about the track that we had, before it was constructed. They imagine that it is perfectly smooth, and that all the cars have to do is to roll round and round. Nothing is further from the truth. Some of the rough parts of the track are as bad as anything which is likely to be met with on the road, if not worse, while in their treatment there is this important difference. A driver on the road eases up for any little unevenness of surface which he sees, and saves his chassis accordingly. That easing up does not occur on the track, where the man has his foot hard down all the time, and takes the bumps as they come. In that difference in the attitude of the driver lies the reason why I do not consider that the braking strains to which a car is put when raced on the road are so intense as the corresponding stresses which come upon the chassis as it bounds from bump to bump, without any relief in the way of a slackening of speed, on the track.

“A car when running at 100 m.p.h. jumps from the track, and may be in the air for, say a third of a second. A little arithmetical calculation will suffice to show that in that time it moves fifty feet, and therefore comes down to earth with the same violence as though it had been thrown, at a speed of roo miles per hour, for a distance of fifty feet. Moreover, while it is in the air the engine is speeding up, and the back wheels, when they hit the ground again, are turning much more quickly than they need, for the speed at which the car is moving. The result is just the same as if the brakes had been applied most violently, and extremely suddenly, much more suddenly than they could ever be applied by hand, for even moving at his speediest, a man takes quite an appreciable time to move the hand lever or pedal and apply his brakes.

“As an example of the improved brake efficiency which results from these gruelling tests,” he continued, “it is an actual fact that Mr. Victor Bruce, when competing in the ‘ Circuit des Routes Payees,’ found his brakes, which acted on the rear wheels only, so powerful that he was run into from behind by other cars equipped with four-wheel brakes.

“On the question of the advisability of holding periodical road races in England, I most certainly think we ought to have them, not only so that British manufacturers should be better able to compete than they are now, in Continental events, but so that we could attract to this country that vast body of overseas, Continental and Colonial buyers, to whom road races are the most attractive form of publicity. That aspect is quite apart from the question as to the comparative value, from the point of view of chassis improvement, of road and track racing. As indicating the value which I personally attach to the track I would point out that we test and perfect our road racing cars on Brooklands.” “Another important part of your activities in the direction of car trials, Mr. Edge,” we went on, ” is in connection with the Official Tests which are conducted by the Royal Automobile Club. In what way do these enter into your general scheme of improving the construction of our cars, and at the same time, pleasing the people you have got.'”

“We carry out tests of that description on our standard products, such as anyone can buy, as distinct from our racing cars. We guarantee that whatever performance is put up by one of our cars under an R.A.C. test can be equalled by any other of the same model which we sell, and if any customer of ours is dissatisfied with his car, in that he claims that it will not perform as, according to these R.A.C. tests, we say it should perform, then we will have it put through the same tests to prove our case, provided of course that he will pay for the test. Obviously we cannot pretend to carry out tests free of charge, for all those of our customers who imagine that their cars fall a little short in performance. The cost would be prohibitive.”

“Finally,” Mr. Edge, “if we do not weary you, what bearing has an Exhibition such as that at Olympia have on this all-important matter ? “