Gerardus Mercator

In 1569, Gerardus Mercator, a Flemish geographer from Belgium, invented a new system of map making. He created a map of the world that was first to plot a curved surface as straight lines.

Mercator used very advanced mathematics, but he based his work on a simple idea. Imagine a paper cylinder wrapped around a globe, touching the globe at the equator. A light bulb placed at the center of the globe casts shadows of longitude and latitude lines onto the inside of cylinder. When the cylinder is rolled flat, longitudes and latitudes come out as straight lines, right angles to one another. forming a grid.

This new kind of map making meant that a constant course followed by ships for long distances could be plotted accurately as straight lines. Mercator's maps helped navigators chart oceans with much greater accuracy and safety.