The internal combustion engine had taken almost 30 years to invent – the first experiments date back to the middle of the 19th century. Research pointed to the idea of four-stroke operation: intake, compression, combustion, exhaust.
The author of the idea, French engineer Alphonse Beau de Rochas, failed to implement it in practice. Nicolaus August Otto, a servant from Cologne and a self-taught inventor, had more luck. On May 9 1876, his ten-year effort brought success – he finally started his engine.
The machine was such a success that it had been manufactured for ten years unmodified. And today, four-stroke engines still purr under the hoods of most cars, the only difference with Otto’s design being the working medium: instead of an gas-air mixture used by the German inventor, modern engines run on gasoline.