Mercator Maps

Date: 1595
Owner: Library of Congress
Source Type: Publications

The "Nova et aucta orbis terrae descriptio ad usum navigatium emendate accommodate," created by the Dutch cartographer Gerard Mercator in 1569, was the first map to mathematically project from a spherical globe onto a two dimensional chart. Known as isogonic cylindrical projection, Mercator stretched out the degrees of latitude near each pole, flattening the globe so as to allow navigators to calculate accurate loxodromes, or straight lines of bearing, without the imprecision inherent to portolan charts. Yet Mercator's maps retained several of the inaccuracies found on other maps of this era, most notably the inclusion of the northwest passage, the waterway connecting the Atlantic and Pacific Oceans north of Canada. Iberian navigators, who had become expert in the creation and use of portolan charts, were slower to adopt projection maps than their contemporaries in northern Europe, and the sciences of navigation and mapmaking pioneered by Portugal and Spain in the fifteenth and sixteenth centuries became outmoded.