JOHANNES DE SACRO BOSCO. Sphæra Ioannis de Sacro Bosco, emendata. Lutetiae [Paris]: Guillaume Cavellat, 1564. - In-8, 165x110: 102 ff. Soft parchment, smooth spine, remnants of binding (period binding). Rare new edition of the Traité de la Sphère in Latin by the mathematician Johannes de Sacro Bosco (...-1256?). Written around 1230, this is one of the works that introduced the basic elements of astronomy. Adopted by the University of Paris, it was the textbook used to introduce students to astronomy from the 13th to the end of the 16th century. Guillaume Cavellat published numerous editions of this text from 1550 until his death, and his widow also continued to publish it. This edition consists of the epistle by humanist Elie Vinet (1509-1587) to Joannes Tacitus, dated Bordeaux March 1, 1550. It is followed by Mélanchton's preface, dated August 1540. Johannes de Sacro Bosco's treatise on the sphere occupies leaves 9 to 51. It is followed by notes by the Portuguese astronomer Pedro Nunes (1502-1578) on the chapter devoted to climates, translated by Elie Vinet, the exposition of the twenty-second passage of the third book of the Epitome of Regiomontanus on Ptolemy's Almagest, an extract from the treatise by the Arab astronomer Alfraganus (07..-0861) on the rising and setting of the planets, a collection of writings on the rising and setting of the fixed stars collected from various authors, explained for students, an abridgement on the sphere by Valeriano Pierio (1477-1560), and a text on eclipses after Proclus. The edition includes over 80 woodcuts, including 3 with volvelles. An interesting copy in a contemporary or slightly later binding, fully interleaved. Johannes de Sacro Bosco's treatise is laden with ancient notes in Latin, in line spaces, in the margins and on the added leaves. These are almost certainly student notes. Some soiling and stains to binding. Binding missing. Title soiled and restored in lower margin. Light staining to varying degrees throughout. Second and seventh leaf shorter margins. Provenance: old signature on title, repeated twice.