James Watt (1736-1819), Scottish engineer. Watt made numerous practical improvements to the steam engine of his day. By 1790 the superior Watt steam engine had completely replaced the older Newcomen variety. His inventions included the double acting engine where the piston is made to both push & pull (1782); the centrifugal governor (the germ of automation), a device that controlled a process by means of variations in the process itself (1788); & the pressure gauge (1790). He was made a Fellow of the Royal Society (1785), refused a baronetcy & lived to be the last surviving member of the Lunar Society.