Beschreibung:

CASSINI, Gian Domenico (Cassini I) (1625-1712). Ephemerides Bononiensis mediceorum syderum ex hypothesis, et tabulis . Bologna: Emilio Maria, & Fratelli de Manolessi, 1668. 2 0 (278 x 195 mm). Typographic tables, a few with woodcut symbols, 2 woodcut initials, type ornament headpiece. (A few leaves lightly foxed.). Contemporary limp vellum, covers gilt panelled. Provenance : 18th-century ms. initials "o i s" on front free endpaper; 19th-century shelfmark label on spine. FIRST EDITION of Cassini's tables of the movements of the four satellites of Jupiter discovered by Galileo. Lacking sufficiently precise and comprehensive observations, neither Galileo nor his successor at the University of Pisa, Vincenzo Renieri, were able to complete these tables, undertaken in hopes of finding a solution to the problem of determining longitude. Thanks to his friendship with the famous Roman lensmakers G. Campani and E. Divini, Cassini was able to obtain powerful telescopes not available to his predecessors. His ephemerides , published shortly before his move to France, were employed for several decades by navigators as an aid in the calculation of longitude, and by other astronomers: Olaus Rhmer, for instance, used them in 1675 for his demonstration that light has a finite speed. They were superseded by more precise tables published by Cassini in Paris in 1693. Riccardi I, 279; Norman 411.