CLOCK

A clock is a fixed instrument for measuring Time, intended to remain in a given location and to indicate the time continuously — as opposed to the watch, designed to be worn on oneself. The term is also strictly distinguished from the pendulum clock, a clock specifically regulated by a pendulum beating the second or half-second and intended for domestic or ceremonial use, “clock” remaining the generic term, whatever the regulating organ — old foliot, Balance–Hairspring (balance spring) or pendulum. A clock brings together a Motor organ (power source) (weight or spring), a transmission Train (wheel train), a regulating organ, and a Display with hands, digits or a rotating Dial; many are equipped with a chime marking the passing of hours or quarters. The term covers various objects: monumental Clock of a bell tower, belfry or station, floor Clock, wall Clock, table Clock or astronomical Clock, additionally indicating calendar and celestial data. Appearing in the Middle Ages in the form of weight-driven Clocks with a foliot, perfected by the invention of the Pendulum in the 17th century then by Quartz and atomic technologies, Clocks have constantly gained in precision and occupy a central place in the social organization of Time.