The geography of the heavens, and class-book of astronomy: accompanied by a celestial atlas (1873)
Burritt, Elijah H. (Elijah Hinsdale), 1794-1838, Mattison, Hiram, 1811-1868, ed, Whitall, Henry, 1819-1887? Celestial planisphere · New York, Sheldon & company · leaf 322
68T. Kinds of telescopes? Dcccribn,Illustration. 688. Simplest form of refracting telescope f TELESCOPES REFRACTORS AND REFLECTORS. 315 689. The Galilean telescope consists of two glasses—a dovbie-tonvex next the object, and a double-concave near the eye. Theformer converges the light till it can… … Here the light is converged by the lens A, till it can be received by the double-concavelens B, by which the rays are made to become a small parallel beam that can enter theeye at C. This was the form of the telescope constructed by Jansen, and improved byGalileo ; on which account it is called the…
Constellations · Stars
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