Perfected by German engineers Nikolaus August Otto, Gottlieb Daimler and Karl Benz in the late 19th century, the internal-combustion engine has a much older history. Early theoretical models used various combustibles, including hydrogen and gunpowder, but two men can lay claim to having invented the gas-powered engine: Samuel Brown and Nicolas Carnot.

Early Gas Engines

Brown’s prototype was a gas-vacuum engine, using a gas-powered flame to create a partial vacuum within a cylinder; atmospheric pressure caused the pump action, explains K.A. Barlow in the “Biographical Dictionary of the History of Technology.” An English cooper, Brown built a model in 1824 and tested a vehicle driven by his engine in Kent in 1826. In 1824, French physicist Carnot published a paper outlining his theoretical engine, which relied on the heat produced by the expansion and compression of a heated gas-air mixture; although his focus was on improving steam engine efficiency, it had a far-reaching influence on thermodynamics and engineering, according to a biography by Mark Crawford for the American Society of Mechanical Engineers. It was Carnot’s model that ended up influencing the development of automobiles most directly, via the work of French engineer Etienne Lenoir and others.