Harrison's eight-day wooden clock movement, 1715.

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.