Astronomy for the use of schools and academies (1882)
Gillet, J. A. (Joseph Anthony), 1837-1908, Rolfe, W. J. (William James), 1827-1910 · New York : Potter, Ainsworth, & Co. · leaf 208
spot,as it might be called, it hasbeen calculated that the sunmust rotate on its axis inabout twenty-five days. 185. The Inclination of theSuns Axis. — The paths de-scribed by sun-spots acrossthe solar disk vary with theposition of the earth in itsorbit, as shown in Fig. 202.We therefore conclude…
Astronomy
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