This map illustrates a projection designed by Turquet, showing the entire world in equidistant concentric circles of latitude, with distortions to the areas at the extreme radii. Named after Guillaume Postel, this projection was based on an earlier projection developed in 1581. 

The Sunderland Collection

This unusual world map is on a north polar Postel azimuthal projection, showing equidistant, concentric circles of latitude. It was finely engraved over two pages on copperplate and published by Louis Turquet de Mayerne. This second edition shows a number of place names and islands not included in the first, including ‘Nouvelle Hollande’ in the Southern Continent, where only the word ‘Beach’ had appeared before.

In his book, Turquet illustrated a number of different projections, but this map is a projection of his own invention, showing us the entire world in one circle. The geographical outline is simplified with the borders of various countries shown but only a few place names. Around the map are panels of text and personifications of the seasons.

Turquet's map first appeared in his 'Discourse Sur la Carte Universelle...' (1648), which covers a number of projection schemes including Gemma Frisius, Pieter van den Keere, Abraham Ortelius, and Guillaume Postel.

Stunningly engraved map on a north polar Postel azimuthal projection (or azimuthal equidistant), this map of the world bears equidistant concentric circles of latitude.

Turquet's World Map on a North Polar Azimuthal Projection