Instrumentum primi mobilis, a Petro Apiano nunc primum et inventum et in lucem editum. Ad cuius declarationem & intellectu[m] pronunciata centu[m] hic proponuntur, e quibus instrumenti nobilissimi usus innotescit & compositio [...]. Accedunt ijs Gebri Filii Affla Hispalensis astronomi [...] libri IX. de astronomia, ante aliquot secula Arabice scriptis, & per Giriardu[m] Cremonensem latinitate donati [...].

Folio: [80]-146-[2 bl.] pp. (sl. toned, minor soiling and spotting in 1st ff., repair to bottom corner of title).

18th-c. mottled sheep, richly gilt flat spine, gilt sides, red edges, marbled endpapers (expertly rebacked with old def. spine pasted on, some corners rep.). Good copy.

Extr. rare original ed. of a major advance in trigonometry: “In this volume Apian published a table of sines that, for the first time, was based on a circle with a radius of a power of ten, in this case one hundred thousand. The values of the functions were thus decimal and were easily adapted to any situation in which the defining circle was a decimal power” (Tomash & Williams). The book also contains the earliest printing of Geber’s (Jabir ibn Aflah; 1st half 12th c.) “De Astronomia”, a reworking of Ptolemy’s “Almagest”, but differing in the positioning of Venus and Mercury in relation to the sun, Geber contradicting Ptolemy by placing them above. Its most important influence was in the realm of spherical trigonometry. Large title woodcut, the figure at right representing ancient astronomy with a celestial globe, the one at left modern astronomy holding an instrument described in the book. Full-page woodcut coat of arms of dedicatee. Numerous sm. woodcut diagrams in text. Title in red and black.
Ref. VD-16 A-3087 (erroneously calling for “[76] Bl.”). - Van Ortroy 107. - Adams A-1292. - Cicognara 3095. - Ind. Aurel. 106.423. - STC German (BL) 37.