This collection of photographs were accumulated in the files of the Sproul Observatory at Swarthmore College. The collection includes 17 photoprints, and includes a key for identifying figures depicted in one of the group photographs. Most of the pictures are group portraits of participants at American Astronomical Society and International Astronomical Union (IAU) meetings, although there are also several other group photographs taken at Johns Hopkins University and Swarthmore College, as well as an autographed photo of astronomer Roy W. Delaplaine.