Perhaps no single work has exerted a greater influence on the development of cartography in the modern world than the Geographia of the ancient astronomer, mathematician, and geographer Claudius Ptolemy (c. 90–168). Ptolemy lived in Alexandria during a time when the Egyptian port was the cultural, commercial, and scientific center of the eastern Mediterranean. He had access to centuries of Greek scientific and mathematical learning as well as to geographical information world travelers brought to the great port. Ptolemy compiled this information into a catalog of more than 8,000 places throughout the ancient world, noting his estimates of their latitudes and longitudes. From these tables, he very likely made his own maps, though none directly attributed to him survives. Renaissance editions of the Geographia typically include 26 regional and world maps derived from the earliest surviving Greek manuscripts of the work dating from the thirteenth century. A Latin translation of the Geographia was completed by the Florentine scholar Giacomo da Scarperia (Jacobus Angelus) about 1406–09, and dozens of manuscript copies from the fifteenth century survive, testifying to the work's influence, both as a model for mapmaking and as a compendium of geographical knowledge.
Here we see the elegant edition (titled Cosmographia) published in Ulm, Germany—the first Geographia to be published outside of Italy and the first to use woodcut maps. This world map demonstrates the extent of Ptolemy's knowledge of Europe, Asia, and Africa. It is drawn on Ptolemy's second projection, which preserves the impression of the earth's curvature. Note that the Indian Ocean is depicted as a closed sea. Both Africa and Asia appear to continue beyond the southern and eastern edges of the map, a clear indication that Ptolemy and his editors recognized that there was more to the earth than what they knew.
The Newberry's collection of editions of the Geographia is one of the most comprehensive anywhere in the world, offering a nearly complete record of this modernization of Ptolemy. Among editions from the fifteenth and sixteenth centuries, the library lacks only one, published in Bologna in 1477. Nearly all were collected by the great London bookseller Henry Stevens and sold by his son Henry Newton Stevens to Edward E. Ayer, whose collection came to the Newberry.