Charles Greeley Abbot (1872-1973)



Charles Greeley Abbot (May 31, 1872 – December 17, 1973) was an American astrophysicist, astronomer and Secretary of the Smithsonian Institution. He was born in Wilton, New Hampshire.

Life
Abbot graduated from Phillips Academy in 1891 and MIT in 1894, with a degree in chemical physics. Samuel Pierpont Langley was looking for an assistant at the Smithsonian Astrophysical Observatory (SAO), and hired Abbot in 1895 because of his skill at laboratory work, despite his lack of experience in astronomy.

Langley focused on aeronautics experiments, while Abbot became acting director of the SAO in 1896. When Langley died in 1906, Abbot succeed him as director (in 1907), and Charles Walcott became Smithsonian Secretary. Abbot, recognizing that the solar constant was badly approximated, proposed a more accurate value of 1.93 cal/cm²/min for the solar constant (the modern value is measured in watts per square meter).

Abbot was secretary of the Smithsonian Institution from 1928 to 1944. Responsible for the observatory's solar observations, he designed and built devices for measuring solar radiation, including a greatly improved bolometer which measured the Sun's inner corona at the 1900 solar eclipse in Wadesboro, North Carolina.

In 1918 Abbot became Assistant Secretary of the Smithsonian. He succeeded Walcott as Secretary in 1928, and guided the Institution through the turbulent years of the Great Depression and World War II.

From 1941 he was an original standing committee member of the Foundation for the Study of Cycles.

Abbot retired as both SAO director and Smithsonian Secretary in 1944, being the first Smithsonian Secretary not to die in office. He delegated the National Museum largely to his Assistant Secretary, Alexander Wetmore, who succeeded him as Secretary in 1944.

Awards
Abbot won the Henry Draper Medal of the National Academy of Sciences in 1910 and the Rumford Prize of the American Academy of Arts and Sciences in 1915.