Verge escapement in mechanical clocks. In the sixteenth century alternative escapements started to appear, but the verge remained the most used escapement for 350 years until mid-17th century advances in mechanics, resulted in the adoption of the pendulum, and later the anchor escapement. Since clocks were valuable, after the invention of the pendulum many verge clocks were rebuilt to use this more accurate timekeeping technology, so very few of the early "verge and foliot" clocks have survived unaltered to the present day. How accurate the first verge and foliot clocks were is debatable, with estimates of one to two hours error per
Anchor escapement to a fork pushed by the pendulum, so the anchor swings back and forth, with the pallets alternately catching and releasing an escape wheel tooth on each side. Each time one pallet moves away from the escape wheel, releasing a tooth, the wheel turns and a tooth on the other side catches on the other pallet, which is moving toward the wheel. The momentum of the pendulum continues to move the second pallet toward the wheel, pushing the escape wheel backwards for a distance, until the pendulum reverses direction and the pallet begins to move away from the wheel, with