Vertical single-cylinder atmospheric gas engine, made by Crossley Brothers Ltd, Openshaw, Manchester, c.1874. No 1224. Two flywheel cylinder atmospheric free piston gas engine. Two flywheels with ratchet gear on driving shaft which allows the piston and rack to be blown up by the expulsion of gas in the cylinder, and the piston falling by vacuum and its own weight, drives the flywheels as the ratchet engines. This was the first type of internal combustion engine to compress the explosive mixture before firing it.
Label embossed on engine shaft: "Otto Langen & Crossley's Patents Crossley Bros Manchester Sole English & Colonial Makers".