James Watt

Watt, James (1736–1819), Scottish engineer and inventor. His first major invention (patented 1769) was an improved steam engine, with a separate condenser air pump, and insulated engine parts. For the manufacture of such engines he entered into partnership with John Roebuck and later (1775), more successfully, with Matthew Boulton. Between 1775 and 1800 he invented the sun-and-planet gear wheel, the double-acting engine, a throttle valve, a pressure gauge, and the centrifugal governor—as well as taking the first steps toward determining the chemical structure of water. He also coined the term horsepower and was a founding member of the Lunar Society.

See also: Steam engine.