4to. Errata leaf at end. 9 engraved folding plates, woodcut title-vignette by Papillon after Charles-Nicolas Cochin, engraved head-pieces, woodcut initials and tail-pieces. (Light marginal toning to plates.) Contemporary speckled calf, rebacked preserving original spine.

FIRST EDITION of the most important work to issue from the Peruvian expedition of 1735-1744, undertaken by the Academy with the goal of measuring an arc of the meridian near the equator, resulting in the determination of the shape of the earth as an oblate spheroid. Alden & Landis 749/35; Norman 285; Sabin 6876.