Who first used the name 'atlas' to define a set of maps?

Gerardus Mercator was a 16th-century German-Flemish cartographer, geographer and cosmographer. He was renowned for creating the 1569 world map based on a new projection which represented sailing courses of constant bearing as straight lines—an innovation that is still employed in nautical charts. Mercator was one of the founders of the Netherlandish school of cartography.