Happy 503rd Birthday to Gerardus Mercator. A cartographer, mathematician, philosopher, inventor, engraver, and teacher, Mercator was a man whose eponymous cartographic projection forever changed how mariners navigate their ships and how we see the world. He was also the first person to call a collection of maps an atlas. Cheers to a great man and an even greater mind.
Below are world maps based on Mercator’s Projection. All the meridians intersect with lines of latitude at 90 degree angles. Alone, this would still skew a line of bearing. To combat this, Mercator proportionally increased the distance between the parallels, so he could match the rate of angular distortion. This projection was widely used for navigation charts during the age of exploration, as any straight line on a Mercator-projection map is a line of constant true bearing that enables a navigator to plot a straight-line course, without having to continuously recalculate his course.