A steam engine is a machine that turns the energy released by burning fuel into motion. Thomas Newcomen built the first crude, but workable, steam engine in 1712. Scottish inventor James Watt vastly improved the device in the 1760's and 1770's. Steam power was later applied to moving machinery in factories and to powering ships and locomotives.
The Earth and Its Peoples A Global History, Bulliet et al, 2005.