Otto, Nikolaus August

Otto, Nikolaus August (nē`kōlous ou`gst ô`tō), 1832–91, German engineer. He was coinventor (1867) of an internal-combustion engine, and he devised (1876) the four-stroke Otto cycle, which was widely adopted for automobile, airplane, and other motors.

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Otto, Nikolaus August

(born June 10, 1832, Holzhausen, Nassau—died Jan. 26, 1891, Cologne, Ger.) German engineer who developed the four-stroke internal-combustion engine. He built his first gasoline-powered engine in 1861, and in 1876 he built an internal-combustion engine using the four-stroke cycle (four strokes of the piston for each explosion), which offered the first practical alternative to the steam engine as a power source. Though the four-stroke cycle was patented in 1862 by Alphonse Beau de Rochas (1815–93), it is commonly known as the Otto cycle since Otto was the first to build such an engine.