Longitude Act passed in July 1714. For details on many of the efforts towards determining the longitude, see History of longitude. The Longitude Act offered a series of rewards, rather than a single prize. The rewards increased with the accuracy achieved: £10,000 (worth over in ) for anyone who could find a practical way of determining longitude at sea to an accuracy of not greater than one degree of longitude (equates to at the equator). The reward was to be increased to £15,000 if the accuracy was not greater than 40 minutes, and further enhanced to £20,000 if the accuracy was not
The Nautical Almanac The Nautical Almanac The Nautical Almanac has been the familiar name for a series of official British almanacs published under various titles since the first issue of "The Nautical Almanac and Astronomical Ephemeris", for 1767: this was the first nautical almanac to contain data dedicated to the convenient determination of longitude at sea. It was originally published from the Royal Greenwich Observatory in England. A detailed account of how the publication was produced in its earliest years has been published by the National Maritime Museum. Since 1958 (with the issue for the year 1960), [[Her Majesty's Nautical Almanac Office]] and