Dr. Ackroyd Stuart


I was very interested in J. B. Perrett's reference to Ackroyd Stuart as during the mid1940s I lived in Chipstable, a small and isolated village in West Somerset which was the base of' a firm of agricultural engineers established in 1847 known as W. H. Pool and Sons.

At that time the younger son, Alfred, was still alive and although then in his seventies was a most clear and lucid man to talk to on anything connected with engineering or science.

Whenever Diesel was mentioned he very bluntly said "Diesel never invented an engine, Father and a clergyman called Ackroyd Stuart invented the compression ignition engine, Diesel only perfected it".

In the '40s the 3 1/2-h.p. prototype and a larger engine were still working in his shops, as were many others on local farms after nearly 50 years' use.

They were horizontal engines run on paraffin or TVO which entered the engine straight through an atmospheric valve with no vaporiser or carburettor and were started by swinging after the head and inlet had been warmed for a few minutes by a cast iron blowlamp which was hinged on the engine frame.

A catalogue of' circa 1905 claims "Royal Letters Patent"; not living near the Patent Office or Science Museum I have never checked up on the patents but this seems to confirm John Perrett's view that Stuart preceded Diesel.

It would be interesting to know more of Stuart, whether he was a clergyman, and whether he worked with Pool or if Pool used his designs under licence?