Astronomy for the use of schools and academies (1882) (14764263865)

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:
Fig. 226. observed by Liais. In this view the petal-like forms, whichhave been noticed in the corona at other times, are espe-cially prominent. Fig. 226 shows the corona of i860 as it was observedby Temple, Fig, 227 shows the corona of 1867. This is interestingas being a corona at the time of sun-spot minimum, ASTRONOMY. 207 Fig. 228 represents the corona of 1868. This is a largerand more irregular corona than usual. The corona of 1869 is shown in Fig. 229. Fig. 230 is a view of the corona of 1871 as seen byCapt. Tupman. Fig. 231 shows the same corona as seen by Fcenander.
Text Appearing After Image:
Fig. 227. Fig. 232 shows the same corona as photographed byDavis. Fig- 233 shows the corona of 1878 made up from severalviews as combined by Professor Young. 204. The Spectrum of the Corona. — The chief line in thespectrum of the corona is the one usually designated as 1474,and now known as the coronal line. It is seen as a dark line 208 ASTRONOMY. on the disk of the sun; and a spectroscope of great dispersivepower shows this dark line to be closely double, the lowercomponent being one of the iron lines, and the upper thecoronal line. This dark line is shown at x, Fig. 234. Besides this bright line, the hydrogen lines appear faintlyin the spectrum of the corona. The 1474 line has been