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A marine chronometer is a precision timepiece that is carried on a ship and employed in the determination of the ship's position by celestial navigation.It is used to determine longitude by comparing Greenwich Mean Time (GMT), and the time at the current location found from observations of celestial bodies.
After Harrison, the marine timekeeper was reinvented yet again by John Arnold, who, while basing his design on Harrison's most important principles, at the same time simplified it enough for him to produce equally accurate but far less costly marine chronometers in quantity from around 1783. Nonetheless, for many years even towards the end of ...
John Arnold was the first to design a watch that was both practical and accurate, and also brought the term "chronometer" into use in its modern sense, meaning a precision timekeeper. His technical advances enabled the quantity production of marine chronometers for use on board ships from around 1782.
Longitude by chronometer is a method, in navigation, of determining longitude using a marine chronometer, which was developed by John Harrison during the first half of the eighteenth century. It is an astronomical method of calculating the longitude at which a position line, drawn from a sight by sextant of any celestial body, crosses the ...
William Harrison (20 May 1728 – 24 April 1815) was an English instrument maker, the son of John Harrison, inventor of the marine chronometer. The Harrison H4 marine chronometer Early life
Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time is a 1995 best-selling book by Dava Sobel about John Harrison, an 18th-century clockmaker who created the first clock (chronometer) sufficiently accurate to be used to determine longitude at sea—an important development in navigation.
Johann Kessels (1781–1849), German-Danish chronometer maker, Altona, marine chronometer and deck watch. Louis Benjamin Audemars (1782–1833), Swiss watchmaker and manufacturer, Le Brassus . Josef Božek (1782–1835), Czech inventor and clockmaker, Prague , precision pendulum clock .
On 21 March 1842, Dent applied for a Patent, to be entitled "Certain Improvements in Chronometers and other Timekeepers". This Patent covered various designs of compensation balance and the invention of a Remontoire for use in Marine chronometers. In January 1843, Dent opened his second premises, at 33 Cockspur Street, just off Trafalgar Square.