The first internal-combustion engine to operate successfully on the four-stroke cycle was built in 1876 by Nicolaus August Otto. His "Silent Otto" was a good machine with a poor theory ...

A four-stroke internal combustion engine operates on the Otto cycle, a design conceived by German-born Nicolaus August Otto as early as 1861 and eventually awarded patent number 365701.

Richard Trevithick’s design had a boiler but this was removed to make the internal combustion engine. The German inventor Nicklaus Otto developed the first four stroke engine in 1876.