Dr. Charles G. Abbot, by Tolman, Ruel P (Ruel Pardee) 1878-1954, June 1935, Smithsonian Archives - History Div, Dr. Charles G. Abbot is seated at a desk in his office in the Smithsonian Institution Building and facing the camera. Papers are on the desk. Dr. Abbot was an astrophysicist, second Director of the Smithsonian Astrophysical Observatory (SAO) (1907-1928), and fifth Secretary of the Smithsonian Institution (1928-1944)..