Internal
Combustion Engine

AMSCO p. 312

Among the most-consequential inventions of the late Industrial Revolution were the internal-combustion engine and, along with it, the gasoline-powered automobile. The automobile, which replaced the horse and carriage in Europe and the United States, offered greater freedom of travel for ordinary people, facilitated commercial links between urban and rural areas, influenced urban planning and the growth of large cities, and contributed to severe air-pollution problems in urban areas.

The internal-combustion engine. The internal-combustion engine generates work through the combustion inside the engine of a compressed mixture of oxidizer (air) and fuel, the hot gaseous products of combustion pushing against moving surfaces of the engine, such as a piston or a rotor. The first commercially successful internal-combustion engine, which used a mixture of coal gas and air, was constructed about 1859 by Belgian inventor Étienne Lenoir. Initially expensive to run and inefficient, it was significantly modified in 1878 by German engineer Nikolaus Otto, who introduced the four-stroke cycle of induction-compression-firing-exhaust. Because of their greater efficiency, durability, and ease of use, gas-powered engines based on Otto’s design soon replaced steam engines in small industrial applications. The first gasoline-powered internal-combustion engine, also based on Otto’s four-stroke design, was invented by German engineer Gottlieb Daimler in 1885. Soon afterward, in the early 1890s, another German engineer, Rudolf Diesel, constructed an internal-combustion engine (the diesel engine) that used heavy oil instead of gasoline and was more efficient than the Otto engine. It was widely used to power locomotives, heavy machinery, and submarines.

The automobile. Because of its efficiency and light weight, the gasoline-powered engine was ideal for light vehicular locomotion. The first motorcycle and motorcar powered by an internal-combustion engine were constructed by Daimler and Karl Benz, respectively, in 1885. By the 1890s a nascent industry in continental Europe and the United States was producing increasingly sophisticated automobiles for mostly wealthy customers. Less than 20 years later American industrialist Henry Ford perfected assembly-line methods of manufacturing to produce millions of automobiles (especially the Model T) and light trucks annually. The great economies of scale he achieved made automobile ownership affordable for Americans of average income, a major development in the history of transportation.