Board of Longitude
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The Board of Longitude was the popular name for the Commissioners for the Discovery of the Longitude at Sea. It was a British Government body formed in 1714 to solve the problem of finding longitude at sea.
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[edit] Origins
The problem of not knowing one's longitude had been ongoing for centuries. Navigators and scientists in many countries had been working on the problem. The establishment of the Board of Longitude was motivated by this ongoing problem and by the 1707 grounding of four ships of Vice-Admiral Sir Cloudesley Shovell's fleet off the Isles of Scilly, resulting in a large loss of life. The Board gathered the greatest scientific minds of its day to work on the problem, including Sir Isaac Newton, and also put up prizes for those who could demonstrate a working device or method.
The main longitude prizes were:
- ₤10,000 for a method that could determine longitude within 60 nautical miles (111 km)
- ₤15,000 for a method that could determine longitude within 40 nautical miles (74 km)
- ₤20,000 for a method that could determine longitude within 30 nautical miles (56 km).
In addition, the Board had the discretion to make awards to persons who were making significant contributions to the effort or to provide ongoing financial support to those who were working productively towards the solution. The Board could also make advances of up to ₤2,000 for experimental work deemed promising.[1]
Even though many tried their hand at winning the prize, for decades none were able to come up with an efficient, practical and relatively economical solution to the problem. The board of longitude recognised that any serious attempt would be based on the recognition that the earth rotates through 15° of longitude every hour. The comparison of time between a known place (eg Greenwich) and the local time would determine longitude. Since local apparent time could be determined with some ease, the problem centred on finding a means of determining the time at a known place.
For details on many of the efforts towards determining the longitude, see History of longitude.
[edit] End of the Board's mandate
In spite of the obvious desirability of such a device by sailors, for many decades a sufficiently accurate chronometer was prohibitively expensive. The lunar distance method was used by mariners either in conjunction with or instead of the marine chronometer. However, with accurate clocks becoming commonplace, John Harrison showed that his method was the way of the future.
With the significant problems solved, the Board of Longitude was dissolved in 1828.
[edit] References
- ^ Taylor, E.G.R., The Haven-finding Art: A History of Navigation from Odysseus to Captain Cook, Hollis & Carter, London 1971, ISBN 0 370 01347 6
