Newcomen, Thomas, blacksmith, born at Dartmouth; invented a steam-engine in which the piston was raised by steam and driven down by the atmosphere after the injection into the cylinder of a squirt of cold water, which cooled it, so that the steam when injected did not raise the piston at once up. By James Watt's invention of a separate condenser it was superseded, and employed afterwards principally for pumping water. The interruption in the movement between the descent and ascent of the piston made it worthless for such purposes as Watt's invention is applied to; (d. 1729).
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Newcastle-upon-Tyne * Newdigate, Sir Roger