The name most associated with the development of the explosion engine operating on the four-cycle principle and compressing the mixture before exploding it is Nicolaus August Otto, Deutz, Germany, who on Aug. 14, 1877, was granted patents covering the four-cycle engine and compressing the mixture. His application was made a year earlier. Otto’s patent had a very far-reaching effect: in fact, it entirely altered the gas-engine situation and started it on the direct road along which development it is still traveling. It displaced the Brayton two-cycle engine that was then the leader. Although Otto receives to-day practically all of the credit and naturally profited very materially because of his patent, the conception of compression and four cycles of operation was not original with him. He was the person who combined these ideas into a practical engine. Otto sold his engine only for stationary applications.