A clock which uses its own weight as motive power and gradually descends a toothed rack which meshes with the first wheel of the train. Winding is effected by pushing the clock to the top of the rack again. The type was popular in south Germany and Austria in the 18th century, especially in a miniature version with a cow tail pendulum which is now being reproduced in quantity. These clocks have the advantage that they rarely run down, because the unbalanced appearance of the movement when it has descended the rack a little way induces one to push it to the top again. A version of this clock was produced in 1919 with a double pendulum beating seconds and a special escapement based on the cylinder escapement used in watches. The advantage of this design was that the clock only fell a short distance and could be used for a mantelpiece or desk.