John Charter’s landmark U.S. patent (no. 292,894), issued Feb. 5, 1884, one of the earliest U.S. engine designs to run on liquid fuels rather than town gas or syngas. Although Charter Gas Engine Co. employee Franz Burger actually invented the engine, he is identified on the patent application only as a witness. The opposed-piston engine used flame ignition exposed at the right moment by slide-valves in the 2-stroke cycle. Note the engine’s flyball governing, the same type of governor used on steam engines.
Illustration courtesy Dr. Graeme R. Quick