Series 1 consists of the papers of Donald Hatch Andrews and dates from 1929 to 1959; it is divided into five subseries. Subseries 1, Subject Files, consists of Andrews' correspondence, arranged alphabetically, covering the period 1929-1946 and 1959. Subseries 2, Chronological Correspondence, covers the years 1923 to 1959. Subseries 3, Speeches, contains Donald Andrews's "Knowledge and Faith" speeches on science and religion, dating from 1945 to 1949. Subseries 4, Films and Notes, consists of films that served as visual aids to Andrews' "Unheard Melodies" talks, which were broadcast on local television. Subseries 1 and 2 include correspondence between Andrews and his colleagues in the Chemistry Department and at other universities, Hopkins personnel, and representatives of various companies. There are also files on special projects which Andrews supervised (such as Project X, a wartime research project), and some on personal activities, such as the Chemical Ballet (in which dancers portray different chemicals and their reactions). The films in subseries 4 show the movement of a drumhead after it has been struck and the motion of a plucked string. The first three films are in very poor condition, as the film is quite brittle and has been spliced with masking tape. The fourth film is devoted to Andrews's "Singing Statue" demonstration at the Baltimore Museum of Art and shows Andrews setting up the apparatus to measure and record the frequencies of the atoms in the statue, bringing these sounds into the audible range. In very good condition given its age (c. 1950), it is the shortest of the four films (about four minutes); the others are approximately eight minutes each. All four films are silent. There are also eight additional films which have not been analyzed. Subseries 5, entitled Files - 1922-1935, 1936-1937, 1937-1938, contain the same types of materials as are found in Subseries 1 and 2. They have been maintained as three separate alphabetical spans to preserve their original systems of organization.