Opus sphericum magistri Joanis de Sacro busco natione angli figuris verissime exculptis ...
1505, ad finem Januarij
4to,  lvs, with 28 large woodcut diagrams in text. Small wormholes in the lower margins of the first 3 lvs, with loss of a few letters. With old annotations. Without final blank. Modern souple vellum binding, green closing ties
Quentell printed the same book already in 1500 with commentaries by Wenzel Faber von Budweis (1455-1518).
Johannes de Sacro Bosco (c. 1195 - c. 1256) wrote a short astronomy textbook, Tractatus de Sphaera, which was widely read and influential in Europe during the later medieval centuries as an introduction to astronomy. Though principally about the heavens it also contains a clear description of the Earth as a sphere, in the first chapter. "The Sphere" was required reading by students in all Western European universities for the next four centuries