Anchor escapement made today use it. Tower clocks are one of the few types of pendulum clock which the anchor escapement did not dominate. The varying force applied to the wheel train by the large exterior hands, exposed to wind, snow, and ice loads, was better handled by gravity escapements. The deadbeat escapement has two faces to the pallets, a 'locking' or 'dead' face, with a curved surface concentric with the axis on which the anchor rotates, and a sloping 'impulse' face. When an escape wheel tooth is resting against one of the dead faces, its force is directed through the anchor's
Escapement was unworkable. Arnold also designed a spring detent escapement but, with improved design, Earnshaw's version eventually prevailed as the basic idea underwent several minor modifications during the last decade of the 18th century. The final form appeared around 1800, and this design was used until mechanical chronometers became obsolete in the 1970s. The detent is a detached escapement; it allows the balance wheel to swing undisturbed during most of its cycle, except the brief impulse period, which is only given once per cycle (every other swing). Because the driving escape wheel tooth moves almost parallel to the pallet, the escapement