The Diamond Pallets of John Harrison's Fourth Longitude Timekeeper—H4

Autor: Jonathan Betts, Derek Pratt, Jonathan Hird
Rok vydání: 2008
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Zdroj: Annals of Science. 65:171-200
ISSN: 1464-505X
0003-3790
Popis: Summary John Harrison (1693–1776) is regarded as the father of chronometry. During his lifetime, he relentlessly pursued one of humankind's greatest and oldest challenges—that of finding the longitude at sea. In succeeding (according to the rules dictated by an Act of Parliament), he bequeathed to humankind the most accurate portable timekeeper the world had ever seen. It is a remarkable fact that his timekeeper, known today as H4, remains more accurate than the majority of expensive mechanical wristwatches manufactured today. Such accuracy required novel approaches to address the various difficulties that befall all mechanical watches, and Harrison overcame many of these with his own innovations. The reduction or elimination of friction is one such problem with clocks and watches, and from an early age Harrison demonstrated his mastery in this subject. This is typified by his choice of woods in his early clocks, and in later clocks by his ‘grasshopper’ escapement. In the 1750s, Harrison's attention switc...
Databáze: OpenAIRE
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