This folder contains correspondence and other documents relating to the introduction of Edison's cylinder phonograph. The correspondents include Edison associate George H. Bliss; Dr. Clarence J. Blake, an ear specialist and acoustic researcher who had been involved in experiments with Alexander Graham Bell; and Alfred M. Mayer, professor of physics at the Stevens Institute of Technology. Also included is a letter from Bell's father-in-law, Gardiner G. Hubbard, who served as president of the Bell Telephone Co. and later as president of the Edison Speaking Phonograph Co.

All of the documents have been selected except for duplicate copies of correspondence.