Turret Clock, English, 1671.
© Science Museum / Science & Society Picture Library
Made by William Clement of London for King's College, Cambridge, this iron clock was in use from 1671 until 1817. In 1819 it underwent considerable restoration by Thomas Safford, a Cambridge clockmaker, and was transferred to St Giles' Church in Cambridge. It is signed on one of the top bars: 'GULIELMUS CLEMENT LONDINI FECIT 1671' (William Clement of London made me in 1671). The timekeeping is controlled by a pendulum through a so-called 'anchor' escapement. Clement was one of the posible inventors of the anchor escapement, which could be used with a smaller arc of swing for the pendulum than the verge escapement which preceded it.