Escapement wheel" gear, allowing the clock's gear train to advance or "escape" by a fixed amount. This regular periodic advancement moves the clock's hands forward at a steady rate. At the same time the tooth gives the timekeeping element a push, before another tooth catches on the escapement's pallet, returning the escapement to its "locked" state. The sudden stopping of the escapement's tooth is what generates the characteristic "ticking" sound heard in operating mechanical clocks and watches. Escapements are used elsewhere as well. Manual typewriters used escapements to step the carriage as each letter (or space) was typed. Historically, a liquid-driven
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