Gerardus Mercator; a Flemish German (5 March 1512 ? 2 December 1594) was a cartographer renowned for creating a 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 used for navigation. In his own day he was the worlds most famous geographer but; in addition; he had interests in theology; philosophy; history; mathematics and magnetism as well as being an accomplished engraver; calligrapher and maker of globes and scientific instruments.