‎"MAUPERTUIS, PIERRE LOUIS MOREAU de.‎
‎Accord de Differentes Loix de la Nature qui avoient jusqui'ici paru incompatibles (15 Avril 1744).‎

‎Paris, L'Imprimerie Royale, 1748. 4to. Recent blue boards. Issued in ""Histoire de L'Academie Royale des Sciences, Année 1744, Paris"", pp. 417-426. Bound with the engraved frontispiece and titlepage to the volume.‎

Reference : 38730

‎First edition. In this importent paper ""Agreement of several Laws that had hitherto seemed to be incompatible"" he showed that the behavior of light during refraction - when it bends on entering a new medium - was such that the total path it followed, from a point in the first medium to a point in the second, minimised a quantity which he again assimilated to action. These results were instances of his later (1748) formulated ""The principle of least action"".‎