For centuries, seafaring explorers and merchants reckoned with the longitude problem. It was relatively easy to figure out a ship’s location on a north-south axis, but nearly impossible to determine how far east or west it was. And the stakes were high. Sail too far astray and your ship (and men) could end up so far afield that getting home before the food and water ran out might be impossible. The sailing world needed better tools to determine location at sea.
In 1714 the British government established the Board of Longitude, offering a cash prize to anyone who could figure out how to detect how far east or west a ship was at sea. The Board was abolished in 1828, but only after fostering innovative techniques that would forever change the nature of marine navigation.
Cambridge University and the National Maritime Museum at Greenwich recently released an archive making all of the letters, objects, and documents related to the Board’s work available, along with a spiffy set of videos that brings the Board’s history and achievements to life.
During the Board’s tenure, clockmaker John Harrison figured out that sailors could find out their location if they knew local time at sea and compared that to the time at a common reference point. The moon was seen as a giant clock, and its position relative to stars was recorded in the Nautical Almanac, giving sailors the data to compare against the time at sea. One of the innovations vetted by the Board of Longitude is John Harrison’s Sea Clock. Also during that time, Greenwich became the prime meridian.
All of this work led to more accurate maps. The Board sponsored journeys, including some aboard Captain Cook’s ships with portable observatories for mapmakers to sketch and use triangulation to determine accurate location on voyages, including one to the Northwestern United States.
You can start rummaging through the fascinating archive here.