born July 5, 1753, Chacewater, Cornwall, Eng.
died March 1815, Penryn, Cornwall
British inventor.
He and his father, Jonathan (171780), worked for James Watt . Seeking to improve on Watt's steam-engine design, he devised the first reciprocating compound steam engine (patented 1781); his engine had two cylinders (see piston and cylinder ), a significant contribution to efficiency . In 1799 it was judged an infringement on Watt's patent.