4to (248 x 190 mm). 21 engraved folding plates. (Some very minor spotting, mostly marginal dampstaining to a few leaves.) Contemporary calf gilt, brown morocco lettering-piece gilt, edges stained red (joints starting, some light wear). Provenance: Early annotation on flyleaf; William S? (signature on title-page). 

FIRST EDITION of Cassini's manual. His principal areas of interest were the study of planets and their satellites, including the structure of Saturn's rings and the observation and theory of comets and the tides. While his observations yielded important results, his biases as a Copernican and not a Newtonian diminished their theoretical value.