This folder contains correspondence and other documents relating to the technical and commercial development of phonographs. Among the documents for 1909 are items pertaining to the process of making cylinder records and to plans for developing diamond reproducing points and disc phonographs. Also included are letters suggesting new applications or improvements for the phonograph, to which Edison responded with marginal comments. Among the correspondents are Edison; Harry F. Miller, his personal secretary; Frank L. Dyer, president of the National Phonograph Co.; George F. Scull, assistant to the president; Carl F. Wilson, general manager; and Alphons Westee, secretary and treasurer.
Approximately 90 percent of the documents have been selected. The items not selected include letters of transmittal and acknowledgment and items that duplicate information in selected material.