In horology, a tourbillon (/ t ʊər ˈ b ɪ l j ən /; French: [tuʁbijɔ̃] "whirlwind") 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 ...
