Maker, Sinclair Harding, England. 2000. 16"h x 8"w x 6"d excluding case. John Harrisons' dual, coupled compound pendulum, 'grasshopper' escapement as applied in his H1 Sea Clock. This escapement arrangement was used in Harrisons' first entry into the competition for England's'  Longitude Board prize of 20,000 BPS in 1735. His H1 had many innovations besides this escapement arrangement. These include, gridiron temperature compensation for the pendulums (later evolving into the bi-metallic spring strip for balance wheel compensation and seen today all mechanical thermostats), spring winding maintaining power, roller pinion, anti-friction arbor pivot supports (later evolved in his H3 into the 'two caged roller bearing). This is the forerunner of roller bearings; ball races, used in all modern machinery. Not one of Harrison's better known accomplishments, but arguably his most important in it's effect on industry. Certainly second only to his solution to the Longitude problem. This solution was, as many are in science, a confluence of achievements. These being temperature compensation, reduction of friction, perfection of the spiral spring escapement remontoire to achieve even power delivery to the escapement (this remontoir was used on H4 which did win the Longitude prize. The coil spring remontoir was used in H3).

John Harrison, in my opinion is second only to Christian Huygens in his contributions to the advancement of horology. Huygens was the first to apply the pendulum to an escapement and to invent the spiral spring balance wheel as used in watches. One could argue that Galileo was first to apply the pendulum, since his drawings do exist to indicate that he had thought of this first, but no evidence exists that he actually produced a working model, and there is no evidence to the contrary that Huygens did not come upon the application of the pendulum to an escapement by his own efforts.

Sinclair Harding is known as one of the commission firms that produces fine quality clocks with superb finishes. This clock is the 8th commission produced in this model.