Suggested Background Reading     NATIONAL GEOGRAPHIC ATLAS OF THE WORLD A key resource for information and maps on all locations around the Earth.   LONGITUDE By Dava Sobel Learn about John Harrison, an English clockmaker, who solved the Longitude Problem by developing a clock that would keep precise time at sea. With that clock, sailors could know what time it was on board and at home when a single event took place on board (i.e. when the sun reached its highest point in the sky). And by knowing the difference in hours and minutes between the two times, they could then calculate their longitude.(More)   SEA CLOCKS By Louise Borden Before the late 1700‘s, ships were often lost or shipwrecked because there was no reliable method to determine longitude at sea. England's Parliament offered a huge reward to anyone who could develop a proven way to measure longitude. Learn how John Harrison solved the "longitude problem" by developing a special clock, and changed history and science forever   This Season Teachers Kids Orientation Registration Search Copyright 1997-2009 Journey North. All Rights Reserved. Questions or comments? Contact us.