Original eight day clock by Harrison, date 1715, wheel work mostly of wood. With correspondence concerning Harrison clocks

This clock was made by the chronometer pioneer, John Harrison (1693-1776), at the age of 22, before he began his celebrated project to build a chronometer accurate enough to find a ship's longitude at sea. Although the design of the clock is conventional it is made almost entirely of wood; partly, it is thought, to reduce the need for lubrication, but also because Harrison was a carpenter by trade. The clock movement was weight-driven and would have been mounted in a long case with a pendulum.