George Graham

George Graham was apprenticed to and later worked in partnership with Thomas Tompion, ultimately inheriting Tompion's workshop and business. He married Tompion's niece and, on Tompion's death in 1713, continued the firm, maintaining its reputation for exceptional quality while making his own significant technical contributions to clock and watch escapements.

Graham is credited with developing the cylinder (horizontal) escapement for watches around 1720s, which allowed noticeably thinner watch movements than the verge escapement it competed with, and with the dead-beat escapement for precision pendulum clocks, which removed recoil and markedly improved the timekeeping of astronomical regulators. He also devised the mercury pendulum, a temperature-compensated pendulum using mercury's expansion to counteract the rod's thermal expansion, keeping a regulator's rate stable across seasonal temperature change.

Graham was elected a Fellow of the Royal Society and worked closely with astronomers, including supplying precision instruments for observatories; his scientific instrument work is as significant to horology's history as his watches. Like Tompion, he was buried in Westminster Abbey, in the same grave.