Escapement remontoire, a device which isolated the escapement from changes in drive force. Without a balance spring, the crossbeat would have been no more isochronous than the verge. Invented around 1657 by Robert Hooke, the anchor (see animation at top of page) quickly superseded the verge to become the standard escapement used in pendulum clocks through the 19th century. Its advantage was that it reduced the wide pendulum swing angles of the verge to 3–6°, making the pendulum nearly isochronous, and allowing the use of longer, slower-moving pendulums, which used less energy. The anchor is responsible for the long narrow shape
Watch Nevertheless, the craftsmanship of mechanical watches still attracts interest from part of the watch-buying public, especially among the watch collectors. Skeleton watches are designed to leave the mechanism visible for aesthetic purposes. A mechanical movement uses an escapement mechanism to control and limit the unwinding and winding parts of a spring, converting what would otherwise be a simple unwinding into a controlled and periodic energy release. A mechanical movement also uses a balance wheel together with the balance spring (also known as a hairspring) to control the motion of the gear system of the watch in a manner analogous to