Editing Board of Longitude (section)

==Origins==
Navigators and scientists had been working on the problem of not knowing a ship's longitude. The establishment of the Board of Longitude was motivated by this problem and by the [[1707 Scilly naval disaster|1707 grounding of four ships]] of Vice-Admiral [[Cloudesley Shovell|Sir Cloudesley Shovell]]'s fleet off the [[Isles of Scilly]], resulting in heavy loss of life. Established by [[Anne, Queen of Great Britain|Queen Anne]] the [[Longitude Act 1714]] named 24 Commissioners of Longitude, key figures from politics, the Navy, astronomy and mathematics.<ref>{{cite web|title=Acts of Parliament and awards|url=http://cudl.lib.cam.ac.uk/view/MS-RGO-00014-00001/19|publisher=Cambridge Digital Library|access-date=22 July 2013}}</ref> However, the Board did not meet until at least 1737<ref>{{cite web|title=Commissioners of Longitude|url=http://cudl.lib.cam.ac.uk/view/ES-LON-00004|publisher=Cambridge Digital Library|access-date=22 July 2013}}</ref> when interest grew in [[John Harrison]]'s marine timekeeper.

The Board administered prizes for those who could demonstrate a working device or method. The main [[longitude prize]]s were:
*£10,000 for a method that could determine longitude within {{convert|60|nmi}} (£{{Inflation|UK|10,000|1714|fmt=c|r=-5}} as of {{inflation-year|UK}})
*£15,000 for a method that could determine longitude within {{convert|40|nmi}} (£{{Inflation|UK|15,000|1714|fmt=c|r=-5}} as of {{inflation-year|UK}})
*£20,000 for a method that could determine longitude within {{convert|30|nmi}} (£{{Inflation|UK|20,000|1714|fmt=c|r=-5}} as of {{inflation-year|UK}}).

In addition, the Board had the discretion to make awards to persons who were making significant contributions to the effort or to provide financial support to those who were working towards a solution.  The Board could also make advances of up to £2,000 for experimental work deemed promising.<ref name="egrtaylor">Taylor, E.G.R., ''The Haven-finding Art: A History of Navigation from Odysseus to Captain Cook'', Hollis &amp; Carter, London 1971, {{ISBN|0-370-01347-6}}</ref> Under this heading, the Board  made many lesser awards, including some awards in total £5,000 made to [[John Harrison]] before he received his main prize, an award of £3,000 to the widow of [[Tobias Mayer]], whose lunar tables were the basis of the lunar data in the early decades of ''[[The Nautical Almanac]]'', £300 to [[Leonhard Euler]] for his (assumed) contribution to the work of Mayer, £50 each to [[Richard Dunthorne]] and [[Israel Lyons]] for contributing methods to shorten the calculations connected with lunar distances, and awards made to the designers of improvements in chronometers.

Even though many tried their hand at winning the main prize, for decades none was able to come up with a practical solution to the problem. The Board recognised that any serious attempt would be based on the recognition that the earth rotates through 15° of longitude every hour. The comparison of local time between a reference place (e.g., [[Greenwich]]) and the local time of the place in question would determine the longitude of that place.  Since local apparent time could be determined with some ease, the problem centred on finding a means of determining (or in the case of chronometers, keeping) the time of the reference place when one is far away from it.

For details of the efforts towards determining the longitude, see [[History of longitude]].