(Berlin, Haude et Spener, 1759). 4to. No wrappers as issued in "Memoires de l'Academie Royale des Sciences et Belles Lettres". tome X, pp. 323-372.
First printing of this paper in which Euler made important research into the field of optics and how to construct glasses with three lenses.
"Euler composed his object-glasses of two bi-convex lenses of crown-glas, and a bi-concave of flint, to form a triple object-glass of six lines focal distance with a large aperture; and it is because our microscope is achromatic that it is established on the principles of Euler." (Brewster. The Edinburgh journal of science. P. 225).
See Eneström E240.
Order-nr.: 44266