July 1914 Issue [Article] The variable sun Download PDF Adjust Share by C.G. (Charles Greeley) Abbot, Subscribe or log in to continue reading. Tags 20th century Astrophysics Bolometer C.G. (Charles Greeley) Abbot Mount Wilson Observatory (Calif.) Observations Plants, Effect of solar radiation on Research S.P. (Samuel Pierpont) Langley Smithsonian Astrophysical Observatory (Washington, D.C.) Sun More from C.G. (Charles Greeley) Abbot The heavens through a spectroscope Adjust Share