Traite de la Comete. Qui a paru en Decembre 1743 & en Janvier, Fevrier & Mars 1744. Contenant Outre les Observations de l'Auteur, celles qui ont ete faites à Paris par Mr. Cassini, & a Geneve par Mr. Calandrini. On y a joint diverses Observations & Dissertations Astronomiques, Le Tout Accompagne de Figures en Taille Douce. by CHESEAUX, Jean-Philippe Loys de (1718-1751) - 1744

Lausanne & Geneva:: Chez Marc-Michel Bousquet, 1744., 1744. 8vo. [2], 308 pp. Title printed in red and black, woodcut title vignette, woodcut headpiece, initial letter, 1 folding table (p. 166), 2 double-page folding tables of lunar observations (between pp. 266(a), 267(b)), 6 folding engraved plates, errata; small repair on verso of title, 2 leaves with waterstaining. Tiny manuscript note on title, recording the author's death date, larger ink ms. also on foot of title: "1744". Original full mottled calf, leather gilt-stamped spine label, raised bands; joints cracked. Very good. Extremely rare. First edition. Cheseaux was a Swiss astronomer who was the first to observe a number of nebulae. Loys de Cheseaux "earned his European reputation as an astronomer thanks to his Traite de la Comete (1744, in which he defends Newton's physics and discusses Olbers' Paradox." – Historical Dictionary of Switzerland. / Halley, having banked his reputation on the predicted return of his comet's return in 1758 spurred similar efforts at understanding the computation and understanding of a comet's orbit by Cheseaux and Leonhard Euler. It was Cheseaux who put together the hypothesis that the 76- and 75-yar periods between returns of the comets seen in 1531, 1607, and 1682, were probably, "two comets, each traveling on identical orbits such that when one comet was at perihelion, the other was close to its aphelion. Their orbital periods were constant and identical. Calculating the interval between the perihelion passages in 1531 and 1682 to be 151 years and 10 days, he predicted that the comet last seen in 1607 could be expected to reach perihelion on November 7, 1758, by the Gregorian calendar. This prediction was given in his 1744 work on the comet of that year. Though not discovered by Cheseaux, this comet is often referred to as Cheseaux's because he computed its orbit and ephemeris and described its impressive, multiple tails." – Yeomans, p. 123. Yeomans, Donald K. Comets; a chronological history of observation, science, myth, and folklore, Wiley, (1991).