tourbillon

1. (horology) A rotating frame, containing the escapement of a clock or watch, that attempts to compensate for the effects of gravity.Examples: "Time was vulnerable to the force of gravity. So Breguet came up with the tourbillon, which isolated the balance wheel and escarpment off on a little platform of their own, geared to the third wheel, rotating about once a minute, assuming in the course of the day most positions in 3-D space relative to the gravity of the Earth, so the errors would cancel out and make time impervious to gravity."; "In their final year, each student must make their own watch with a complication—from a tourbillon to a chiming mode to having a date display."