Books on sound recording:Tyndall, John: On Sound, 6th edition, 1896; Seymour, Henry: The Reproduction of Sound, n.d.; Mitchell, Ogilvie: Talking Machines, n.d. (circa 1922); Clements-Henry, B: Gramophones and Phonographs, 1923; Brown, B: Talking Pictures, 1932; Miller, D.C.: Sound Waves, Their Shape & Speed, 1937, d.w. (6)