Early petrol engine. Historical artwork of early designs for an electrical generator (top left) and locomotives, using petrol as their fuel source. These were based upon the 1860 design by Lenoir, which used an electrical spark to ignite petrol in a cylinder, which then produced rotary motion by driving an axle. This was a forerunner of the internal combustion engine. Such engines were potentially more efficient than steam engines because rather than using a fuel to heat up a liquid to produce a gas, the fuel produced the gas directly. Taken from Brockhaus Konversations Lexikon 1895.