Includes minutes, 1910-1955; general office files, 1930-1962; correspondence and other records, 1930-1965: financial records,Pierce, G 1919-1970; tutorial record cards, 1939-1964; and Physics Research Library correspondence, 1930-1964, accession records, 1929-1967, and office files. Correspondence concerns research and other contracts, scholarships, pre-and post-World War II cyclotrons, and wartime work at Harvard, departmental projects, among other subjects. Correspondence with and about various Harvard physics professors, organizations, and committees, such as Associates of Physical Science, Western Electric Co. Cyclotron Committee, and Committee on Research in Nuclear Science. Financial records include account books, 1940-1958, for the Cyclotron Committee and Physical Laboratory and correspondence and other documents relating to departmental funds. Other material includes photographs of persons, apparatus and buildings; blueprints of University of California Cyclotron; and questionnaires, 1886-1888, and other information about physics teachers in secondary schools.