Combustion ignition engines

Sir,

Mr. Stickland (July Motor Sport) is quite correct that Rudolf Diesel is normally regarded as the successful developer of c.i. engines rather than being the original inventor. The original patent is usually taken to be that of Herbert Akroyd Stuart and Charles Richard Hinney, number 7146 of 1890, originally applied for on May 8th 1890 and accepted on January 17th 1891. Akroyd Stuart, the Ackroyd spelling is not used in any of his three patents of 1889/1890, is described as mechanical engineer of Bletchley Iron & Tinplate Works and Nutley as consulting engineer of Hackney Road, Middlesex.

The engine described in patent 7146 has a permanent igniter within the cylinder and it is this feature, dispensing with an external igniter and vapouriser, together with a suction stroke drawing in air alone and not a fuel-air mixture that makes it the true progenitor of what is now generally termed the "diesel" engine.

Jewkes, Sawers and Stillerman in their standard work "The Sources of Invention" state that "... in 1891 he (Stuart) sold a licence to manufacture his engines... to the company now kniiwn as Ruston and Hornsby ..." and also record that Professor William Robinson of University College, Nottingham advised him on his experiments.

This is by no means the only case where inventions predate either the time or person normally thought to be the in R. Baker's book of 1976, "New and Improved", lists various of these, the pneumatic tyre for one.

London WC2 R. HALL Deputy Director (Services) The British Library