On the probable existence of a magnetic field in sun-spots
By: by George E. Hale
Series: Contributions from the Mount Wilson solar observatory -- no. 30
Published: 1909
Place of publication: Chicago
Language: eng
Number of pages: 29
Subjects: Sunspots
Notes: Cover-title.

At head of title: Carnegie institution of Washington.

"Reprinted from the Astrophysical journal. vol. XXVIII, p. 315-343, 1908."

Bibliographical foot-notes.