Family correspondence, 1882-1950; general correspondence, 1891-1952, including letters from Evan Pan Jones and George M. Ll. Davies; important correspondence with Sir Oliver Lodge, 1885-1941, concerning experiments in telegraphy etc.; correspondence, laboratory notebooks, files etc., relating to Ben Davies's work for Sir Oliver Lodge and the Eastern Telegraph Company, 1892-1946; correspondence with Messrs Bibby & Sons Ltd., 1928-1951, about agricultural experiments; papers about spiritualism, 1894-1943, including notes of communications by mediums; files of correspondence, circulars etc., concerning movements such as the Union of Democratic Control, 1914-1949, and the Fellowship of Reconciliation Committee, 1915-1922; diaries, 1884-1950; pocket diaries and notebooks, 1894-1908; bound volumes and files of press cuttings including articles by Ben Davies; manuscript and typescript drafts of his publications, lectures and articles, with offprints, pamphlets and booklets; and files, 1915-1918, concerning experiments on the detection of submarines conducted by Ben Davies on behalf of the Admiralty.