John Arnold (watchmaker)

John Arnold ( * 1736 in Bodmin, Cornwall, † August 25, 1799 in Eltham, Kent) was a watchmaker and inventor very reliable marine chronometers. He wore his work decisively to the solution of the linear problem.

Longitude Act

Because we could not determine or only very inaccurate longitude, ships and crews were lost again and again. Also you had to sail much longer distances without knowledge of longitude. In 1714, the British Parliament began, in a solution to the length problem, a reward of 20,000 pounds from, for that time a very considerable sum of ( A ship then cost about 2000 pounds). One can determine the longitude, if one knows a reference time of a place known length, must carry this on a ship with an accurate clock that displays the time of the output port of the whole trip away. Any inaccuracy of the clock leads to an error in the length calculation.

Inventions

John Arnold improved the then watches significantly. He invented a new type of inhibition and simplified the movements. The chronometer could be built as cheaply and in large numbers. He also established the first pocket chronometer ago. By special precision manufacturing held its watches the harsh conditions of a voyage, stood and walked very carefully. An exact time measurement was possible for the first time and thus the accurate determination of longitude. It was only in 1805, six years after his death, his contributions have been recognized by the Commission longitude and paid half the ausgelobten money to his son John Roger Arnold.