The gas engine is an internal combustion engine, as distinguished from a steam engine; its power is generated in a cylinder. Gasoline or crude oil is a common fuel. Experiments by Froschman, Lenoir and the German, Otto, 1860-5. marked the beginnings of the gas engine. The gasoline engine employs a carburator for mixing the gasoline and air; then the mixture enters a cylinder, where it is ignited by an electric spark; this explosion drives the piston, which communicates the energy to a wheel or shaft.