Latitude      Changed   Knowledge of the World  What Changed		Without Latitude   In 1440 European Sailors Only   Knew    But With Latitude   In 1516 They Knew                Once latitude could be established accurately, ships could sail the entire world. Precise longitude was far less important.* Ships Beacons Maps Latitude Compass Roses Earth's Magnetism Traditional Sailing Science of Sailing Coastal Navigation Ocean Currents Ocean Weather Longitude Polynesian Astronomy Math in Maps Calendars Site Map Net Resources Learning Page   Patricia Seed © 1998-2011 Comments sepia maps © Huntington Library Loading Why the Chinese could never have sailed to America in 1421