Tractatus de Sphaera von Johannes de Sacrabosco in einem Druck von 1581. Es handelt sich um einen Klassiker der Astronomie, der das Wissen der Antike und der Araber verband. Auf Büchern wie diesem bauten Galileo und Kepler auf. Sacrabosco ist auch interessant, weil er schon 1250 die arabischen Zahlen benutze (eingebunden an das Buch).

Siehe Interview youtube: https://youtu.be/xOAd-Tic7IQ

Bilder: https://commons.wikimedia.org/wiki/Category:De%20sphaera%20mundi

Sacrobosco's De sphaera mundi was the most successful of several competing thirteenth-century textbooks on this topic. It was used in universities for hundreds of years and the manuscript copied many times before the invention of the printing press; hundreds of manuscript copies have survived. The first printed edition appeared in 1472 in Ferrara, and at least 84 editions were printed in the next two hundred years. The work was frequently supplemented with commentaries on the original text. The number of copies and commentaries reflects its importance as a university text.

Though principally about the universe, De sphaera 1230 A.D. contains a clear description of the Earth as a sphere which agrees with widespread opinion in Europe during the higher Middle Ages, in contrast to statements of some 19th- and 20th-century historians that medieval scholars thought the Earth was flat.