Astronomy for schools; upon the basis of Mons. Arago's lectures at the Royal observatory of Paris .. (1841)
Arago, F. (François), 1786-1853, Haskins, Roswell William, [from old catalog] ed · New York, Robinson, Pratt & co.; · leaf 106
, in appearance, from thegeneral complexion of the sun. Their forms are veryirregular, and their duration exceedingly variable;and they are usually surround:d by a penumbra, or THE SUN. 103 imperfect shadow. They are almost always com-prised within a zone of which the extent varies, northand south… … Suppose a b c, Fig. 23, the sun, and d e f spotsupon its disk; the interiour portions of which areblack, while the surrounding penumbra is of a lightershade. Much ingenuity has been expended in endeavoursto explain the nature and character of these spots.Some have imagined that the sun, from which…
Astronomy
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