Bianchini, Francesco

Hesperi et phosophori nova phænomena sive observationes circa planetam Veneris. Rome: Giovanni Maria Salvioni, 1728



Folio (15¾ x 10¼ in.; 400 x 260 mm). Title-page printed in red and black with engraved vignette, engraved frontispiece portrait of John V of Portugal by Pozzi, 10 engraved plates (4 folding), 3 engraved text illustrations, 1 woodcut text diagram, 2 engraved historiated initials, 1 engraved headpiece and 1 engraved tailpiece. Modern half calf, plain endpapers, edges sprinkled red.



First edition of the first atlas of the planet Venus, and the first work to describe the rotation of Venus around its own axis in its path around the sun and its constant inclination (75^{o) to the plane of its own orbit around the sun}.

Ashforth/Linda Hall Library Faces of the Moon, 11; Brown, Astronomical Atlases, p. 139; Riccardi I:132 

Huygen's work on the dark spots of Venus prompted Bianchini to figure out the planet's rotation, which allowed the spots to be seen clearly. His grasp of the inclination and rotation of the planet was not advanced until the twentieth century.  For his observations, the astronomer and mathematician used Roman lensmaker Giuseppe Campani's 25' and 35' aerial telescopes, which are illustrated on two of the folding plates. In addition, there is a small engraved text illustration depicting "the lunar crater, Plato at the right, with Aristotle and Eudoxus at left, and the mountain range of the Alps cut by the dramatic slash of the Alpine valley. Bianchini noted with surprise that the valley did not appear on the great Cassini map, and he was right; Bianchini was the first to see and to portray this most impressive of lunar valleys" (Ashforth/Linda Hall, Faces of the Moon).  Bianchini also observed that the crater at top center was pictured but not named on the Cassini map. It was later named, aptly enough, after Cassini.