Scope and Contents From the Collection: Personal correspondence from 1935 to 1946 is housed in box 1. The correspondence consists primarily of letters from Keuffel to his parents. Box 2 contains personal correspondence from 1961 to 1973 and includes letters from Betty, Warren (Keuffel's son), Ken (Keuffel's brother), professional correspondence, Christmas cards, and letters of condolence pertaining to Keuffel's death (1974) written to the Cosmic Ray Group, a University of Utah research team of which Keuffel was the primary...