The Clockmakers Company collection was started in 1814 and is the oldest specific collection of clocks and watches in the world. It has been on permanent public display in the Guildhall Library since 1874. It is on display in a single room containing at any one time approximately 600 English and European watches, 30 clocks and 15 marine timekeepers, together with horological portraits. The majority of the items range from 1600. The most important items in the collection are probably the marine timekeepers, examples of which include a silver deck watch by Thomas Earnshaw (used by Captain Cook) and a 5th marine timekeeper, made by John Harrison and completed in 1770.