The attainment of the mighty speed of 379 miles an hour by an officer of the Royal Air Force (Flight Lieutenant Stainforth) is fresh in our minds and we honour the pilots, the aircraft builders and the engine constructors who made this possible. We remember also, I hope, the scientific workers, whose investigations afforded the basis on which so much else was built. When one contemplates motion at such speeds as this, one cannot help speculating where such enterprise will lead. The power to move is not new; railways and roadways give abundant evidence of high speed, but motion along them is almost entirely in two dimensions. It is only when the freedom of the air makes three-dimensional motion possible that the problem appears in its greatest and most interesting aspect. In the air there is combined the greatest possible freedom with the highest possible speed, and it is this combination which makes the study of such intense scientific interest. Moreover, the flight path may be greatly curved and that curvature may be in any plane. Great forces may then arise and act upon the aircraft from any side. It is not for nothing that the pilot is strapped into his seat.