File:The story of the sun, moon, and stars (1898) (14778929245).jpg

Identifier: storyofsunmoonst00gibe (find matches)
Title: The story of the sun, moon, and stars
Year: 1898 (1890s)
Authors: Giberne, Agnes, 1845- (from old catalog)
Subjects: Astronomy
Publisher: Cincinnati, National book company
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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a smallplane-mirror in the center of the tube, from whichthey are thrown, parallel to the side of the tube, to theeye-piece, which converges them to the eye. The mirror of a reflector can be made very muchlarger than the object-glass of a refractor. The fa-mous Lord Rosse telescope, which has a tube sixtyfeet long, contains a mirror no less than six feet indiameter. This, to an observer, is tantamount tolooking at the stars with an eye so huge that its pupilalone would be nearly equal in size to the six-footwheel of a steam-engine. It will readily be perceivedhow much more starlight can be grasped by such afishing-net than by the tiny pupil of your eye ormine. A main difference between the two kinds of tele-scope thus resides in the fact that the star-rays—orany other kind of light-rays—when first captured, I^ATER ASTRONOMY. 407 pass, in one case, through the glass on which theyfall, and, in the other case, are thrown off from themirror. In both cases, the whole amount of light so
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S^S^sS eye-piece; of the uck telescope. captured is gathered into a small compass, so as to beavailable for human sight. Once more, let me remind you, it should be alwayskept clearly in mind that every object that is seen by 408 STORY OF THE SUN, MOON, AND STARS. us—from a mote of dust to a sun, from a coal-scuttleto a star—is perceived purely and solely by the lightwhich it gives out, either intrinsic or reflected light.Countless myriads of rays pass from the surface of thething seen to our eyes, picturing there, on the sensi-tive retina, a fleeting vision of its form. All the leading Governments in Europe have ob-servatories for the study of the heavens, which arefurnished with the best instruments of modern con-struction. The principal obseivatories are those atParis, Berlin, Vienna, Nice; Dorpat, the seat of a cele-brated university founded by Gustavus Adolphus, ofSweden, in 1630; Pulkowa, near St. Petersburg; Lis-bon, and at Greenwich in England. In America,though only in rec

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