Beschreibung:

D'Alembert (Jean le Rond) Recherches sur la Precession des Equinoxes, et sur la Nutation de l'Axe de la Terre, dans le Systeme Newtonien, first edition, 4 folding engraved plates, occasional foxing, Paris, chez David l'aine, 1749; Reflexions sur la cause Generale des Vents, first edition, engraved title-vignette and head-piece by Delafosse after Eisen, 2 folding plates, some foxing and browning, the latter especially to margins of first few leaves, [Honeyman 806; Norman 34], Paris, chez David l'aine, 1747, both in contemporary French mottled calf, spines gilt in compartments with red morocco labels, paper spine label to upper compartments, slightly rubbed, 4to (2) ⁂ Two important works: the first mentioned "The precession of the equinoxes, a problem previously attacked by [Alexis] Clairaut, was very difficult. D'Alembert's method was similar to Clairaut's, but he employed more terms in his integration of the equation of motion and arrived at a solution more in accord with the observed motion of the earth" (DSB). Second mentioned: The Réflexions sur la cause générale des vents contains the first general use of partial differential equations in mathematical physics, and in 1746 the original Latin version was honoured with the prize medal by the Berlin Academy of Science. The Paris edition of 1747 is divided into two parts, the first of which includes the writing translated into French by d'Alembert himself; the original Latin version follows in the second part.