I have just been reading a brief description of these ancient gas
engines in a 1950 model engineering magazine and wonder if any still
exist. The Dawson engines had an odd mechanism for rotating the piston
to open ports in the cylinder walls, thereby avoiding any valve gear.
They were made in 1894/1895 by the Paris Singer Syndicate in Clapham,
and running on town gas were supplied to run workshop machinery or
Anyone know any more about these engines?
I checked my 1898 "Gas & Petroleum Engines" book but the only
reference to a Dawson was an Oil Engine. (No details) see
No further reference in the book.
All helpful info. The patent search has got me to patent 12097 of 1895
which is primarily to do with the gubbins to fuel an oil engine but
refers back to patents 6407, 9865 and 6952 in relation to using the
rotating piston to open and close the valves, allowing a normal 4-
stroke cycle. So thats the correct Dawson. However I can't locate
these earlier patents in the database, maybe I am not using the
correct search term.
The article in ME Vol102, Edition 2546 has a photo of a Dawson engine,
and an account from someone who worked on their production. They were
4 inch bore and water or air cooled, and they also made a 2.5inch bore
engine that they experimented with in a bicycle frame using liquid
fuel. Almost certainly the first British motorcycle - albeit an
If anyone has a copy of the Model Engineer for Sept 1st 1949, that
apparently triggered the article I have, as someone discovered one of
these engines and requested information. There was also an article on
them in The Motor magazine on October 28th 1942 - but I don't expect
that to be easy to find.
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