Lever escapement escapement was invented by British clockmaker Thomas Mudge around 1755, and improved by Abraham-Louis Breguet (1787), Peter Litherland (1791), Edward Massey (1800), and its modern ("table roller") form was developed by George Savage in the early 1800s. Since about 1900 virtually every mechanical watch, alarm clock and other portable timepiece has used the lever escapement. The advantages of the lever are, first, that it is a "detached" escapement, it allows the balance wheel to swing completely free of the escapement during most of its oscillation, except when giving it a short impulse, improving timekeeping accuracy. Second, due to "locking" and
Escapement main advantage of the deadbeat is that it eliminated recoil. In the deadbeat, the pallets have a second curved "locking" face on them, concentric about the pivot on which the anchor turns. During the extremities of the pendulum's swing, the escape wheel tooth rests against this locking face, providing no impulse to the pendulum, which prevents recoil. Near the bottom of the pendulum's swing the tooth slides off the locking face onto the angled "impulse" face, giving the pendulum a push, before the pallet releases the tooth. This was the first escapement to separate the locking and impulse actions of