Tractatum de spera quatuor capitulis distinguimus ... Theorica planetarum

Titles from opening lines on p. 1 and explicit on p. [81].
The Sphaera mundi is by Joannes de Sacro Bosco. The Theorica planetarum is usually considered to be by the Cremona astrologer Gherardo da Sabbioneta, although some authorities ascribe it to the Gerardus Cremonensis who died 1187. Cf. Dict. of scientific biog., suppl., p. 189 for a summary of the evidence.
Possibly the 1st printed edition. Cf. The awakening interest in science during the first cent. of printing / Margaret Bingham Stillwell. no. 63, 70.
Imprint from Goff.
This version of the two texts makes reference to diagrams which are not printed with the texts, leaving blank spaces for them.
Signatures: [1¹⁰ 2¹² 3-4¹⁰].
Goff J-400
Hain-Copinger 14106
LC copy: the 1st diagram space is filled in, in ink; the others remain blank. Paragraph marks in alternating red and blue; capitals in alternating red and blue with penwork of the opposite color. Capitals on 1st page of each work in magenta, blue, green, white, and gold. Inscription on p. 84: Hic liber est mei Antonij Vitellij, artib[us] stude[n]ti [sic], que[m] emi Venetijs 7em [libris (= lire)] die 8[v]o Madij 1472. Bookplate of Hans Rosenberg.
Contains manuscript annotations.