Astronomy for the use of schools and academies (1882)
Gillet, J. A. (Joseph Anthony), 1837-1908, Rolfe, W. J. (William James), 1827-1910 · New York : Potter, Ainsworth, & Co. · leaf 43
Fig. 28. The largest reflecting telescope vet constructed is that ofLord Rosse, at Parsonstown, Ireland. Its speculum is 6 feetin diameter, and its focal length 55 feet. It is commonly usedas a Newtonian. This telescope is shown in Fig. 27. The great telescope of the Melbourne Observatory,… … Fig. 29. reflector. Its mirror of silvered glass is 4 feet in diameter, and its focal length is 23 feet. This telescope is shown inFig. 29. 21. The Suns Motion among the Stars, — If we notice ASTRONOMY. 2J the stars at the same hour night after night, we shall findthat the constellations are…
Astronomy
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