Sharpless, Isaac, 1848-1920, Philips, G. M. (George Morris), 1851-1920, joint author · Philadelphia, J.B. Lippincott company · leaf 59
Fig. 14.—A Group of Sun-spots. (From Youngs The Sun.) 5* 54 ASTRONOMY. 40. Phenomena and Cause of Sun-spots.—The spots arecertainly great cavities in the surface of the sun, thebottom of the cavity forming the umbra, and the sides … Fig. 15.—The Changes in the Appearance of a Sun-spot as it is carriedacross the Suns Disk by the Rotation of the Sun. (From Newcombs Pop-ular Astronomy.) the penumbra. This is shown by the appearance of aspot as it is first brought into view by the revolutionof the sun. This may be seen in Fig. 15.…
Astronomy
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
