(Berlin, Haude et Spener, 1770). 4to. No wrappers, as issued in "Mémoires de l'Academie Royale des Sciences et Belles-Lettres", L'Année 1763, tome XIX, , pp. 235-254 + pp. 255-266 + pp. 267-291. Lambert's paper: pp. 292-310.
First printing of all 4 papers. D'Alemberts letters to Lagrange deals with the mathematical treatment of a problem that taxed the minds of the major mathematicians of the day, discussing Bernouilli's and Eulers solutions on the vibrating string. D'Alembert had introduced the wave-equation in physics for the first time in in 1747.
Lambert made importent contributions to the theory of equations.
Order-nr.: 45526