Anchor escapement his precision regulator clocks. However it was actually invented around 1675 by astronomer Richard Towneley, and first used by Graham's mentor Thomas Tompion in a clock built for Sir Jonas Moore, and in the two precision regulators he made for the new Greenwich Observatory in 1676, mentioned in correspondence between Astronomer Royal John Flamsteed and Towneley The deadbeat form of the anchor escapement is less tolerant of inaccuracy in its manufacture or wear during operation and was initially used only in precision clocks, but its use spread during the 19th century to most quality pendulum clocks. Almost all pendulum clocks
Escapement to a point close to its unstable state, and is released with a snap each swing of the balance wheel to give the wheel an impulse, after which it is cocked again by the wheeltrain. The advantage claimed is that since the blade imparts the same amount of energy to the wheel each release, the balance wheel is isolated from variations in impulse force due to the wheeltrain and mainspring which cause inaccuracies in conventional escapements. Parmigiani Fleurier with its Genequand escapement and Ulysse Nardin with its Ulysse Anchor escapement have taken advantage of the properties of silicon flat springs.