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 42
inferior to theNewtonian ; but the latter is subject to the inconvenience,that the observer must be stationed at the upper end ofthe telescope, where he looks into an eye-piece screwedinto the side of the tube. ASTRONOMY. 25 ()n the other hand, the .Cassegrainian Telescope is pointeddirectly at the… … 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,…
Astronomy
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
