The verge escapement is the earliest form of mechanical escapement, the part of a clock or watch that releases the power of the driving weight or spring in regular steps. It consists of a crown wheel with saw-like teeth and an upright arbor, the verge, carrying two pallets that alternately engage the teeth, allowing the wheel to advance one tooth at a time.
The verge appeared in European clocks in the late thirteenth or fourteenth century, originally regulated by a swinging bar or wheel known as a foliot or balance. After the application of the pendulum to clocks in the 1650s, the verge was combined with a short, quick-swinging pendulum, an arrangement that remained standard in English bracket clocks for much of the eighteenth century because it tolerates being moved and set slightly off level. It was also used in watches for several centuries. In longcase clocks the verge was largely superseded by the more accurate anchor escapement from the 1670s. Many bracket clocks were later converted to anchor escapement, so a clock retaining its original verge is generally more desirable. Collectors and restorers look for the crown wheel and pallets, the bob pendulum and evidence of any conversion or reconversion.
