The impressive opus “Tractatus de Sphaera/De Sphaera Mundi” (“On the Sphere of the World”), written by Johannes de Sacrobosco (John of Holywood) around 1230, and its reception in numerous early-modern commentaries and extended copies accumulated and imparted the practical knowledge on elementary spherical astronomy and cosmography for more than five centuries. This important cosmological bestseller, which was reproduced until the 17th century, was not only used at universities, but also studied by various merchants and travelers.

The investigation, which is part of a postdoctoral project on “Maps, Globes and Texts: Cosmographical knowledge in early Modern Europe” at the CIUHCT (University of Lisbon/Portugal), intends to analyse for the first time in detail the role of cartographic/cosmographical representations in the sphere (as maps of the terrestrial sphere with the winds, climate zones etc., volvelle charts and geographical schemes of the world system with the spheres) and its changes in the different incunabula. For that purpose, the collection of printed commentaries of “The Sphere” and a new database compiled by Matteo Valleriani will be used.

In addition to that, the cartography on contemporary manuscripts (as the so-far unknown cosmography by Sebastian Binderlius, compiled in Vienna around 1518, and rediscovered by Thomas Horst recently in three manuscripts) will be compared as well as the transfer of knowledge with Renaissance terrestrial/celestial globes.