Description: [caption id="" align="aligncenter" width="410" caption="Loyal B. Aldrich of the Smithsonian Astrophysical Observatory (1908-1955) and Astrophysicist Charles Greeley Abbot (Fifth Secretary of the Smithsonian, 1928-1944) playing tennis behind the Smithsonian Institution Building, next to the Smithsonian Astrophysical Observatory, in the South Yard, 1920, by Unidentified