Paris: Gauthier-Villars, 1921. Wraps. 19 x 12 cm. 12mo. 129pp. Grey wraps. The front cover is detached and chipped but present, the rear cover is missing. Spine is missing but text block is still holding. French language text. Reprint of the 1729 edition. Fair. Item #66794
"Bouger is remembered today principally by his work on photometry, and by his expedition to Peru in 1735 to carry out a measurement of a degree of latitude, thus contributing to the solution of the important problem of the figure of the earth." - Essai d'optique sur la gradation de la lumière. Nature 111, 320 (1923).