In horology, a tourbillon is an addition to the mechanics of a watch escapement to increase accuracy. It was developed around 1795 and patented by the French-Swiss watchmaker Abraham-Louis Breguet on June 26, 1801. In a tourbillon the escapement and balance wheel are mounted in a rotating cage, in order to negate the effects of gravity when the timepiece is stuck in a certain position. By continuously rotating the entire balance wheel/escapement assembly at a slow rate, the tourbillon averages out positional errors.
