Nikolaus August Otto

Beginning his working life as a travelling grocery salesman in Cologne, Otto became increasingly obsessed with the emerging technology of the day - namely gas and steam.

The big news at the time was Jean Joseph Etienne Lenoir's invention - an engine that burned natural gas. It was attached to a cart, and though it moved under its own power, the engine was grossly inefficient and noisy. Otto believed he could improve things with a liquid fuel and began experimenting.

He built his first gas engine in 1861 and formed a partnership with German industrialist, Eugen Langen. Originally known as NA Otto & Cie, the company still operates as Deutz AG. By happy accident, Otto recognised the value of the compression of the fuel air mixture before burning. The idea of the four-stroke piston cycle - or 'Otto Cycle' - was born.

Spending the next five years tweaking and developing the design, Otto finally won a gold medal for his 'atmospheric gas engine' at the 1867 Paris Exposition.