The twentieth century has seen man’s mastery of the air, and fundamental to that achievement has been the provision of power to sustain the process of flight. For the first forty years the piston engine reigned supreme, yet for even longer now the power to fly has been provided by the gas turbine. In the conception and development of this prime mover Britain can justly claim to have led the world.

Two servants of the Crown quite independently had the vision and that amalgam of creative and analytical powers to see what might lie beyond the piston engine — one a scientific civil servant working at the Royal Aircraft Establishment (RAE) and the other, remarkably, a young RAF officer already distinguishing himself as a pilot. But the birth of the jet engine proved to be a painful process. While early aircraft designers had embraced the piston engine, neither Government nor the aircraft or aero engine industry showed interest initially in the gas turbine. The change in attitude began when war approached in 1939 and thereafter accelerated in the effort to move from bench demonstrator status to a full-production engine capable of contributing to the outcome of the war. It was in this difficult and complex process of transition that Dr Harold Roxbee Cox — Lord Kings Norton — was to play such a vital role. To appreciate his achievements it is appropriate to remind ourselves of the progress — or lack of it — on the gas turbine prior to his becoming involved.