BEAU DE ROCHAS, ALPHONSE(-EUGNE)

born April 9, 1815, Digne, Fr. died March 27, 1893, Vincennes French engineer who originated the principle of the four-stroke internal-combustion engine. His achievement lay partly in his emphasizing the previously unappreciated importance of compressing the fuel-air mixture before ignition. Beau de Rochas patented his idea in 1862 but did not build such an engine, leaving the development to others. As a result of the work of Nikolaus A. Otto of Germany and tienne Lenoir of France, four-stroke engines almost completely displaced all other types of internal combustion engines and came into universal use.