Latitude and Longitude

The measurement of longitude is important both to cartography and to provide safe ocean navigation. Mariners and explorers for most of history struggled to determine precise longitude. Finding a method of determining exact longitude took centuries, resulting in the history of longitude recording the effort of some of the greatest scientific minds. Accurate navigation was extreemly difficult until a marine chronograph was discovered by englishman John Harrison 1773. I have blipped couple of model boats against a background of a book "measuring the World" I love reading books and histories of nautical nature.