New Archive Reveals How Scientists Finally Solved the Vexing “Longitude Problem” During the 1700s

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.

Relat­ed Con­tent:

Caught Map­ping: A Cin­e­mat­ic Ride Through the Nit­ty Grit­ty World of Vin­tage Car­tog­ra­phy

Play Cae­sar: Trav­el Ancient Rome with Stanford’s Inter­ac­tive Map

Cut­ting-Edge Tech­nol­o­gy Recon­structs the Bat­tle of Get­tys­burg 150 Years Lat­er

Kate Rix writes about edu­ca­tion and dig­i­tal media. Fol­low her on Twit­ter @mskaterix or vis­it her on the web at .