Trevithick, Richard (trĕvˈĭthĭk) [key], 1771–1833, British engineer and inventor, b. Cornwall. He is known as the father of locomotive power because of his invention (1800) of the high-pressure steam engine. He built a steam carriage that on Christmas Eve, 1801, in London, carried the first passengers transported by steam power. In 1804 a steam locomotive he constructed was used in Wales on a railway, the first vehicle to be so operated. Trevithick also developed steam engines for use in mines and invented a steam threshing machine.