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 158
a kind of microscope to magnify the image already formed bythe object glass. Huygens further improved this form of instrument by applying an eye-piece consisting oftwo convex lenses, which had the effect of giving a more distinct image than a single lens. THE REFKACTING TELESCOPE. In order to make… … A Object Glass. B Concave Flint Lens. Fig. 25. The Refracting Telescope. C Concave Eye-piece.I) Convex Eye-piece. E Modern Achromatic Eye-piece.F Focus of Object Glass. is also increased, and the smaller the diameter.of the object glass in proportion to the length of focus, themore perfect the…
Astronomy
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