British instrument maker and inventor famed for his astronomical instruments as well as his clocks and watches. Apprenticed to a London clockmaker in 1688, George Graham took over the business in 1713 then perfected the first successful deadbeat (or recoilless) escapement for clocks in 1715. For nearly 200 years it was standard equipment in observatories. In 1721, he invented the mercury compensation pendulum and the cylinder escapement for watches. Graham also developed a 5 feet (1.52 m) mural quadrant with telescopic sights in 1742 as well as other astronomical instruments.