| 1. |  | Dr. A. Estelle Glancy and Dr. Edgar D. Tillyer at work on a calculation, at the American Optical Southbridge | Tillyer, Edgar D. (Edgar Derry), 1881-1973; Glancy, Anna Estelle 1883-1975; Optics -- Technological innovations; American Optical Company; Southbridge (Mass.)--Biography--Pictorial works. | Dr. A. Estelle Glancy, mathematician shown working with Dr. Edgar D. Tillyer, Director of Research at the American Optical Company in Southbridge, where they are both seated at a desk. Books, ledgers,... |
