Swiss clockmaker who exerted a major influence both as director of the École d'Horlogerie in Geneva and as a consummate craftsman. In 1766, at the age of 23, he invented the independent-seconds mechanism, a breakthrough that was important in its own right and for the stimulus it gave to the development of chronographs. Ten years later, with Robin and Breguet (1747-1832), was among the very first on the Continent to take an interest in Thomas Mudge's (1715-1794) lever escapement. Perfected the divided lift.