The Discovery of Longitude

Discover the fascinating story behind one of the most important changes to nautical navigation. Long ago, sailors risked their lives, cargo, and ships when traveling the seas. They followed the shoreline, navigating by recognizable landmarks and the stars, but often became lost or wrecked upon rocky coasts. Those who traveled the waters wanted more; they wanted to be able to consistently, and safely, navigate across oceans. To do so, they needed to know three things: latitude, longitude, and direction. A good ship’s captain could use a sextant, compass, and certain stars to find direction and latitude, but he needed to know the time, both on the ship and at a reference point, to find longitude. Unfortunately, an accurate source of time measurement at sea did not exist.