James Watt
Also called: Watt
Scottish engineer whose steam engine with a separate condenser, adapted to give rotary motion, became the power source of factories
Born in Greenock, Scotland, the son of a shipwright and merchant, he trained for a year as an instrument maker in London and then worked as scientific instrument maker to the University of Glasgow. Before his steam-engine business succeeded he earned his living surveying canals. His partnership with Boulton made him wealthy, and he also invented a copying press for letters. He belonged to the Lunar Society of Birmingham with scientists and industrialists, and he used the unit of horsepower to express an engine’s power in terms of horses.