Even from the early days of 1860, when your countryman Wenham experimented with gliders, the development of aerodynamics has been a systematic search for facts. The well–directed efforts of Wilbur and Orville Wright to search out the fundamentals of flight gave a profound impetus to contemporary and later experimenting, and libraries have been filled with the orderly research of aeronautical science. The development of manufacturing practice, however, has been dictated by the immediate needs of the moment, largely without the benefit of methodical study.

I trust I shall not be suspected of pleading a case either for the art of manufacturing, or for aeronautical science, as in the early days it was not unusual for me to find myself designing with one hand, while, in a manner of speaking, manufacturing with the other.

Although there is one successful high–speed heavy-oil engine employing aif injection, it will not be disputed that the present rapid development of this type of internal combustion engine would not have taken place if a high-pressure air-compressor were an essential accessory. It is perhaps well to emphasise that from the beginning designers of engines of the pure “compression-ignition” type have striven after airless injection of the fuel, the first successful application in this connection being that of Sir James McKechnie, of Vickers, Ltd., in 1910. Subsequent development work by Professor Hawkes and others under the Admiralty brought this method to practical success on submarine engines, and it is interesting to note that as late as 1920 almost all experience with airless injection had been gained in this country.

Engines which are the lineal descendants of these early engines, namely, those in which the fuel is injected directly into a combustion chamber of simple form, and known conveniently as the “direct–injection” type, constitute an important section of those engines working successfully at high speeds.