A very fine example of the Venetian edition of Ptolemy's 'Geographia'. This is the first illustrated edition of Ptolemy's work in which an attempt was made to update the information given on the maps based on new knowledge, via recent firsthand accounts and the only Italian edition of Ptolemy to feature woodcut maps.

It is also one of the earliest examples of two-colour printing in cartography, with the major regional names printed in red, others in black, using inset type. Woodward suggests that the dual-colour printing style is done to mimic contemporary portolan charts, which used black and red to distinguish toponyms of various importance. The text in the book says that it used the maps of navigators to update Ptolemy's original work, and the influence may also have extended to the aesthetic.

Sylvanus had already produced an edition of Ptolemy in Naples in 1490, but this was to be based on different principles. He explains in a preliminary note that Ptolemy's work must be updated, and adds that as Ptolemy himself used the work of navigators, so will he. Sylvanus was trying to tread a delicate line between critics of Ptolemy's work and those who appreciated the framework provided by the classical geographer (Dalche).

The atlas includes two world maps, one drawn to Ptolemy's specifications and the other using contemporary geographical knowledge. The modern cordiform world map is only the second map in a Ptolemaic atlas to show America, and the first western printed map to indicate Japan. Sylvanus uses a cordiform map projection, a style developed through the Renaissance to symbolise the link between inner emotions and the external world (Brotton). Sylvanus's method was subsequently adapted by Petrus Apianus and Giovanni Vavassore. In this projection, the degrees on the central meridian were in correct proportion to those of the parallels. Whereas every other map in the atlas is printed on the reverse of other maps or texts, this is blank on the reverse. This map was Sylvanus's attempt to update the picture of the world presented by Ptolemy.

The Americas are shown in three unconnected parts: "terra laboratorum", "terrae Sancta Crucis" (South America) and "terra cube". "Terra laboratorum", or North America, was supposedly named after the labourer who saw it first, according to an inscription on the Wolfenbüttel 1534 world map. The projection used distorts the coastline of South America almost unrecognisably; the words "canibalum romon" appear in the north, a product of common contemporary belief about native cannibalism.

The outline of eastern Asia follows Ptolemy and retains the 'Tiger Leg' used by Martin Waldseemüller and Giovanni Contarini, and the Ptolemaic name "Catigara". Japan appears, named "Zampagu ins", and is shown correctly as an island for the first time. A previous depiction by Ruysch identified Japan with one of the islands discovered by the Spanish in the Caribbean. Asia's coastline is left open to the east, as is the western coast of the Americas, allowing for the possibility that they were contiguous. The map is labelled in the style of Ptolemy; rivers and mountain ranges are shown and named, but very few place names appear. The entire continent of Europe contains only "magna Germa", "Italia" and "dalma".

An earlier owner, Francisco de Chiapanis, has made extensive manuscript notes in the preliminary text of the atlas. He seems to have been particularly interested in the mathematical basis of Ptolemy's work, with diagrams and calculations working out ideas in the text. Francisco also approved of the editor's tone in the book, noting "Modestia Auctoris" next to a line apologising for the author's inexperience.