English: Diagram of a cylinder escapement, an escapement used in pocketwatches from the 18th to the 20th century. from "Tidens naturlære" (Nature of time) 1903 by Poul la Cour, Ill. 27. An escapement is a linkage in a mechanical watch that gives the timekeeping balance wheel pushes to keep it swinging and at each swing allows the watch's gear train to advance a fixed amount, moving the hands forward at a steady rate. The cylinder escapement was invented by Thomas Tompion in 1695 and perfected by George Graham in 1726. It was widely used in inexpensive Swiss and French pocketwatches from the mid-19th century to the 20th century. One attraction was that it was much thinner than the previous escapement, the verge escapement, allowing watches to be made fashionably slim. The book is digitized at s:da:Tidens Naturlære