Lessons in astronomy including uranography. A brief intoductory course without mathematics (1896)
Young, Charles A. (Charles Augustus), 1834-1908 · Boston, London, Ginn and company · leaf 267
ars arecontinually reached. With the ordinary plates and exposure-times not exceeding twenty minutes, it is now possible to getdistinct photographs of stare that the eye cannot possibly seewith the same telescope. Fig. 71 represents the photographic telescope (fourteeninches diameter, and eleven… … FlG. 71. — Photographic Telescope of the Paris Observatory. § 337] STAR MOTIONS. 255 Professor Pickering of Cambridge, U.S., is also planning an inde-pendent work of the same kind, with an instrument having a four-lens object-glass of twenty-four inches diameter and eleven feet focus.It will take…
Astronomy
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