Constant force escapement A constant force escapement is a type of escapement that runs via a continuous source of power. Typically found in watches, this type of escapement will run regardless of whether the watch is fully wound or nearly unwound. The earliest known clock with a constant force escapement was the Huber Timekeeper, a chronometer made between 9 June and 31 October 1755 by the clock- and watchmaker Thomas Mudge. It is known as the Huber Timekeeper because Mudge followed the instructions and design of the Basel mathematician and astronomer Johann Jakob Huber (b. 1733, d. 1798). In summer 1755, Huber was in London and commissioned Mudge to build the instrument’s clockwork. Huber brought the chronometer back with him to Basel. In 1829, it was left to the scientific ‘cabinet’ of the University by his son, the mathematician Daniel Huber, and is now housed in the Historisches Museum Basel in Switzerland (Inv. 1960.20). For an example of an early timekeeper that uses a constant force escapement, see the Mudge Green Chronometer, made by Thomas Mudge in 1777.
