escapement

A wristwatch movement simulated gear by gear. The balance wheel is a differential equation beating six times a second. Everything else, the hands, the perpetual calendar, the year, the moon, the winding rotor, is geared to it. The wall clock never corrects the physics; the drift below is measured, not set. It wears a steel case; scroll, and the watch comes apart in one motion, the case first, then the movement, stratum by stratum.