First edition of these two important astronomical works.
I/ First edition of this very complete treatise, in which the author engages in an original research of the value of the main digital elements of astronomy, and which contains historical details which are still interesting today.
Houzeau & Lancaster n°9251 ; Lalande p. 411 ; Poggendoff I. 380 pour les "éléments" ; Poggendoff I. 390 pour les "tables" ; D.S.B. III, p.10.
He presents it in his preface as the first treatise on elements of astronomy written in French. The work begins with considerations on the circles of the sphere, the systems of the world, astronomical refractions and parallax; it continues with the treatise which is divided into 9 parts: the first deals with fixed stars, the second deals with the sun and its revolution around its axis, the third with the theory of the moon, the fourth with Saturn, the fifth with Jupiter, the sixth with Mars, the seventh with Venus, the eighth with Mercury and the ninth with the satellites of Jupiter and Saturn.
The "Elements" are illustrated with 21 folding plates engraved by Simonneau.
II/ First edition of Cassini’s Tables that serve as a complement to the Elements. Those tables have long been considered the best.
The "Tables" are illustrated with a vignette engraved by Thomassin and 5 folding plates engraved by Simonneau.
"In astronomy proper Cassini's work is vast. Besides working patiently as an observer and directing frequently effective work while head of the Paris observatory he published a great number of memoirs in the Histoire de l'Académie and two books on astronomy (1740): a collection of tables and a manual. Cassini's principal areas of interest were the study of the planets and their satellites... particularly the inclination of the orbits of the satellites and the structure of Saturn's ring... the observation and the theory of the comets, and the tides." (DSB).
Precious copy complete with the “Tables” of Cassini as well as the “addition to the tables”, also complete with its 26 folding plates, preserved in its uniform contemporary bindings with very elegant spines.