Diesel engine: internal combustion engine invented by Rudolph Diesel in 1897. In 1892, Diesel (1858-1913) patented a design for a new type of internal combustion engine. Research into his invention was subsidised by the German armaments manufacturers Krupps. In 1897 Diesel produced a 25 horsepower, four-stroke, single vertical cylinder compression engine, the high efficiency of which, together with its comparative simplicity of design, made it an immediate commercial success. Subsequent royalty fees brought great wealth to its inventor. From Grande Encyclopedie Practique de Mecanique et d'Electricite by H Desarces. (Paris, c1910).