BOSCOVICH, Ruggero Giuseppe (1711-1787). De inaequalitatibus quas Saturnus et Jupiter sibi mutuo videntur inducere praesertim circa tempus conjunctionis. Rome: ex Typographia Generosi Salomini, 1756.

First edition of Boscovich’s work on the aberrations observed in the orbits of Saturn and Jupiter from the predicted Newtonian paths. Isaac Newton had suggested in the second and third editions of his Principia that the observed perturbations in the motions of Jupiter and Saturn were a consequence of gravitational interaction, but neither he nor Flamsteed could devise equations to solve the problem. Taking into account the Earth, this was a version of the classic three-body problem of determining the paths of three moving bodies which affect each other’s gravitational field, and which has no rigourous algebraic solution, and requires approximation techniques. As a result, the Paris Académie des Sciences proposed a competition on solving the problem in 1748, 1750, and 1752, with Clairaut and d’Alembert acting as judges. They awarded the prize to Euler for the years 1748 and 1752, but the 1750 prize remained unassigned. Boscovich had submitted a paper on a proposed solution, which received an honorable mention and was considered for publication in the Mémoires of the Academy, but he wasn’t awarded the prize. He decided to expand his paper, the result of which was the present work. Riccardi I.1 179 n 49; Sommervogel I 1840 n 61.

Octavo (201 x 130mm). Woodcut ornaments and initials, 4 folding engraved plates at end (some spots). Contemporary vellum with gilt spine label, red speckled edges.