The geography of the heavens and classbook of astronomy; (1863)
Burritt, Elijah H. (Elijah Hinsdale), 1794-1838, Mattison, Hiram, 1811-1868, Whitall, Henry, 1819-1887? Celestial planisphere. [from old catalog] · New York, Mason brothers; Boston, Mason & Hamlin; [etc., etc.] · leaf 324
REFLECTIXG TELESCOPES. 702. The Reflecting Telescope is one in which the light is con-verged to a focus by means of a concave metallic reflector orspeculum. Like the Refractors, they may be constructed withvery little mounting ; though for convenience in use, it is neces-sary to place the reflector… … In this cut, the light A is seen passing from the object on the right, and falling uponthe concave surface of the reflector at B, from which it is reflected back to a focus, andenters the eye of the observer at C. This telescope has no eye-piece. 703. The focal distance of a concave reflector is…
Constellations · Stars
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