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 Invented around 1657 by Robert Hooke, the anchor (see animation at top of page) quickly superseded the verge to become the standard escapement used in pendulum clocks through the 19th century.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
Mechanical energy steam engine converts heat energy to mechanical energy. Energy is a scalar quantity and the mechanical energy of a system is the sum of the potential energy which is measured by the position of the parts of the system. The kinetic energy which is also called the energy of motion: The potential energy, "U", depends on the position of an object subjected to a conservative force. It is defined as the object's ability to do work and is increased as the object is moved in the opposite direction of the direction of the force. If "F" represents the conservative force