Charles Greeley Abbot, astrophysicist and Secretary of the Smithsonian, with his device: a silver-disc pyrheliometer which measures direct beam solar irradiance ca. 1913-1917
Charles Greeley Abbot, astrophysicist and Secretary of the Smithsonian, with his device: a silver-disc pyrheliometer which measures direct beam solar irradiance ca. 1913-1917
Charles Greeley Abbot, astrophysicist and Secretary of the Smithsonian, with his device: a silver-disc pyrheliometer which measures direct beam solar irradiance ca. 1913-1917.