Sauzay, A. (Alexandre), 1804-1870 · London, S. Low, son, and Marston · leaf 271
ON OPTICAL GLASSES, 247 placed in a ring adapted to the eye-piece, dims the rays sufficiently to prevent the too dazzling light from injuring the sight of the observer. The third is that little glass placed by the side of the greater one, and whose object it is difficult to understand, convinced as… … Fig. 61. — ASTKONOMICAL TELESCOPE. which it is fixed. If we may be allowed the comparison, we shall say that this small glass, termed a finder^ renders the astronomer the same service that the dog renders the sportsman, for it, like the dog, finds diwdpomts. The immensity of the field open to the…
Glass manufacture · Glassware
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
