Whose Invention Was the Steam Engine?

While Thomas Newcomen built the first practical steam engine in 1712 (used to pump water from mines), it was Scottish inventor James Watt (1736-1819) who transformed it into a versatile power source. In 1765, Watt realised that Newcomen engine wasted enormous energy by repeatedly heating and cooling the cylinder. He introduced a separate condenser, which improved fuel efficiency by about 75%. Further innovations — the double-acting engine, the governor, and the rotative mechanism — made the Watt engine suitable for powering factories, mills, and eventually locomotives. His partnership with Matthew Boulton commercialised the technology. The unit of power, the watt, is named in his honour.