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Events on Wednesday 18 November 1761 2
1761Harrison's H4 marine chronometer sails for JamaicaThe decisive sea trial of a longitude watch beginsWilliam Harrison sailed from Portsmouth aboard HMS Deptford with his father John Harrison's H4 watch to test it on the voyage to Jamaica. On arrival the watch had lost only about five seconds. The trial showed that longitude could be found at sea with a timekeeper.
1761Harrison's H4 marine chronometer sails for JamaicaThe decisive sea trial of a longitude watch beginsWilliam Harrison sailed from Portsmouth aboard HMS Deptford with his father John Harrison's H4 watch to test it on the voyage to Jamaica. On arrival the watch had lost only about five seconds. The trial showed that longitude could be found at sea with a timekeeper.