A PROJECTION [link to glossary entry] created by Ptolemy (c100-170CE) [link to biography entry] . Combining two classical concepts: “oikoumene”, or the “known world”, Eratosthenes’s (c240 BC) calculation that the circumference of the earth was 39,690 km; and Marinus of Tyre’s (c70-130AD) idea of a network of meridians and parallels on which to plot coordinates. This enabled the projection of the geographic coordinates of about 8,000 places.

Ptolemaic Projection of a world map set against a blue sky with illustrations of clouds and 12 Wind Heads