GRAHAM, GEORGE

born c. 1674, , Horsgill, Cumberland, Eng. died Nov. 20, 1751, London eminent English watchmaker who invented the dead-beat escapement. Graham was apprenticed to a London watchmaker and came to the notice of the renowned watchmaker Thomas Tompion. After completing his apprenticeship, Graham succeeded to Tompion's business and to his reputation as the best watchmaker of his time. He perfected the cylinder escapement designed by Tompion, which had been patented by Barlow, Houghton, and Tompion in 1695, as well as the dead-beat escapement, in which the escape wheel remains stationary when not moving forward. This combination produced a degree of accuracy surpassed only by Riefler 170 years later and was extensively adopted in the trade. During the terms of Edmond Halley and James Bradley as astronomers royal, Graham produced instruments to their specifications for the observatory at Greenwich. He also made astronomical devices for the French Academy of Sciences, and, for Charles Boyle, 4th Earl of Orrery, he originated the device now called the orrery, a clockwork model showing the motions of the planets around the Sun.