Astronomy for the use of schools and academies (1882) (14761144871)

Identifier: astronomyforuseo00gill (find matches)
Title: Astronomy for the use of schools and academies
Year: 1882 (1880s)
Authors: Gillet, J. A. (Joseph Anthony), 1837-1908 Rolfe, W. J. (William James), 1827-1910
Subjects: Astronomy
Publisher: New York : Potter, Ainsworth, & Co.
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress



Text Appearing Before Image:
the satellites are shownFig. 289. Fig. 290 shows the transit of one of the satellites, andof its shadow, across the disk of the planet. THE RIXGS OF SATURN. 270. General Appearance of the Rings. — Saturn is sur-rounded by a thin flat ring lying in the plane of its equator.This ring is probably less than a hundred miles thick. Thepart of it nearest Saturn reflects little sunlight to us : so thatit has a dusky appearance, and is not easily seen, althoughit is not quite so dark as the sky seen between it and theplanet. The outer edge of this dusky portion of the ringis at a distance from Saturn of between two and threetimes the earths diameter. Outside of this dusky part of 262 ASTRONOMY.
Text Appearing After Image:
Fig. 291. ASTRONOMY. 263 the ring is a much brighter portion, and outside of thisanother, which is somewhat fainter, but still so much brighterthan the dusky part as to be easily seen. The width of thebrighter parts of the ring is over three times the earthsdiameter. To distinguish the parts, the outer one is calledring A, the middle one ring B, and the dusky one ring C.Between A and B is an apparently open space, nearly twothousand miles wide, which looks like a black line on thering. Other divisions in the ring have been noticed attimes; but this is the only one always seen with good tele-scopes at times when either side of the ring is in view fromthe earth. The general telescopic appearance of the ringis shown in Fig. 291.