For cenÂturies, seaÂfarÂing explorÂers and merÂchants reckÂoned with the lonÂgiÂtude probÂlem. It was relÂaÂtiveÂly easy to figÂure out a ship’s locaÂtion on a north-south axis, but nearÂly imposÂsiÂble to deterÂmine 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 getÂting home before the food and water ran out might be imposÂsiÂble. The sailÂing world needÂed betÂter tools to deterÂmine locaÂtion at sea.
In 1714 the British govÂernÂment estabÂlished the Board of LonÂgiÂtude, offerÂing a cash prize to anyÂone who could figÂure out how to detect how far east or west a ship was at sea. The Board was abolÂished in 1828, but only after fosÂterÂing innoÂvÂaÂtive techÂniques that would forÂevÂer change the nature of marine navÂiÂgaÂtion.
CamÂbridge UniÂverÂsiÂty and the NationÂal MarÂitime MuseÂum at GreenÂwich recentÂly released an archive makÂing all of the letÂters, objects, and docÂuÂments relatÂed to the Board’s work availÂable, along with a spiffy set of videos that brings the Board’s hisÂtoÂry and achieveÂments to life.
DurÂing the Board’s tenure, clockÂmakÂer John HarÂriÂson figÂured out that sailors could find out their locaÂtion if they knew local time at sea and comÂpared that to the time at a comÂmon refÂerÂence point. The moon was seen as a giant clock, and its posiÂtion relÂaÂtive to stars was recordÂed in the NauÂtiÂcal Almanac, givÂing sailors the data to comÂpare against the time at sea. One of the innoÂvaÂtions vetÂted by the Board of LonÂgiÂtude is John Harrison’s Sea Clock. Also durÂing that time, GreenÂwich became the prime meridÂiÂan.
All of this work led to more accuÂrate maps. The Board sponÂsored jourÂneys, includÂing some aboard CapÂtain Cook’s ships with portable obserÂvaÂtoÂries for mapÂmakÂers to sketch and use triÂanÂguÂlaÂtion to deterÂmine accuÂrate locaÂtion on voyÂages, includÂing one to the NorthÂwestÂern UnitÂed States.
You can start rumÂmagÂing through the fasÂciÂnatÂing archive here.
RelatÂed ConÂtent:
Play CaeÂsar: TravÂel Ancient Rome with Stanford’s InterÂacÂtive Map
CutÂting-Edge TechÂnolÂoÂgy ReconÂstructs the BatÂtle of GetÂtysÂburg 150 Years LatÂer
Kate Rix writes about eduÂcaÂtion and digÂiÂtal media. FolÂlow her on TwitÂter @mskaterix or visÂit her on the web at .