Clocks associated with John Harrison, 18th century

John Harrison (1693-1776) was an English clockmaker who is widely regarded as one of the most important horologists in history. He is best known for his development of the marine chronometer, a highly accurate timepiece that made it possible to determine a ship's longitude at sea.

Harrison was born in Foulby, Yorkshire, England, and began his career as a carpenter and clock repairman. In 1728, he was awarded a government prize of £20,000 (equivalent to several million pounds today) for his design of a marine chronometer that could accurately measure longitude at sea.

Over the course of his career, Harrison designed and built several more marine chronometers, each of which was more accurate and reliable than the last. His fourth and final chronometer, known as H4, was completed in 1759 and was tested on a voyage to Jamaica in 1761. The chronometer proved to be highly accurate, more... enabling the ship's captain to calculate the longitude of the ship with an error of just a few miles. This was a major breakthrough in navigation and helped to make ocean voyages much safer.

Harrison's work on the marine chronometer earned him worldwide recognition and he was awarded the Copley Medal by the Royal Society in 1749 and again in 1765. Despite his achievements, Harrison faced significant opposition and criticism from members of the scientific establishment, who were reluctant to accept the idea of a clockmaker from a humble background challenging their authority.

In addition to his work on the marine chronometer, Harrison also made important contributions to the design of other clocks and watches, including the grasshopper escapement and the bimetallic strip. He died in London in 1776, having made a lasting impact on the field of horology and navigation. less...