Anchor escapement the teeth first, protecting the delicate points from being broken. The deadbeat escapement (below) doesn't have recoil. One way to determine whether an antique pendulum clock has an anchor or deadbeat escapement is to observe the second hand. If it moves backward slightly after every tick, showing recoil, the clock has an anchor escapement. The shaft of the anchor, called the "crutch" ends in a fork which embraces the shaft of the pendulum, giving it transverse impulses. The pendulum rod is hung from a short straight suspension spring attached to a sturdy support directly behind the anchor. The pivot of
Anchor escapement it unwinds. An escapement in which changes in drive force do not affect the rate is called isochronous. The superior performance of the deadbeat over the recoil is due to improved isochronism. This is due to the different ways changes in drive force affect the swing of the pendulum in the two escapements: When the deadbeat was invented, clockmakers initially believed it had inferior isochronism to the anchor, because of the greater effect of changes in force on the pendulum's amplitude. Recent analyses point out that the nonisochronism of the anchor can cancel the circular error of the pendulum. That