Ericsson hot air engine, 19th century. Illustration of a hot air engine design, first produced in the 1820s, by Swedish-US inventor and engineer John Ericsson (1803-1889). Also called the caloric engine, air is repeatedly heated and cooled in a cylinder to move a piston. A hot air engine is distinct from a steam engine or an internal combustion engine. Artwork from 'Chaudieres et Machines a Vapeur' (1911) by French civil engineer Max de Nansouty (1854-1913), part of the 'Les merveilles de la science' series of 1867-1891 by Louis Figuier.