Nikolaus Otto was born in Holzhausen was born in 1832. As a young man he began experimenting with gas engines and in 1864 joined with two friends to form his own company. His first atmospheric engine was completed in 1867.
Five years later he was joined by Gottlieb Daimler and Wilhelm Maybach and together they produced the idea of the four-stroke cycle. First described in 1876, the stroke is an upward or downward movement of a piston in a cylinder. In a petrol engine the cycle begins with the induction of a fuel mixture as the piston goes down on its first stroke. Going up, the piston compresses the mixture in the top of the cylinder. An electric spark ignites the mixture, and the gases produced force the piston down on its third, power stroke. On the fourth stroke the piston expels the burned gases from the cylinder into the exhaust.
Otto's patent was invalidated in 1886 when it was discovered that another inventor, Alphonse Beau de Rochas, had already described the four-stroke cycle principle in a privately published pamphlet.
Nikolaus Otto died in 1891.