A popular handbook and atlas of astronomy, designed as a complete guide to a knowledge of the heavenly bodies and as an aid to those possessing telescopes (1891)
Peck, William, Sir, 1862-1925 · New York, G. P. Putnam's Sons · leaf 160
t on some other principle. In 1639 Mersenne suggested the employment of a spheri-cally-shaped mirror, for forming an image which might, as in the case of the refracting telescope, be afterwardsmagnified by means of a small convex lens. The Scottish astronomer Gregory, of Aberdeen, proposed a… … Figs. 27, 28, 29. Different Kinds of Eeflecting Telescopes. The Reflecting Telescope : A, Large speculum ; B, Small concave mirror ; C, Convex mirror;D, Small flat mirror; E, Eye-piece; F, Focus of large speculum. instead of the spherical one, for forming the image, and proposed the use of a small…
Astronomy
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