This folder contains correspondence and other documents relating to the technical and commercial development of phonographs. Among the items for 1908 are documents pertaining to the development of Edison Amberol Records, to recordings made by Leo Tolstoy, to audits of the various Edison companies, and to advertising done by the National Phonograph Co. through the firm of Calkins & Holden. Also included are items regarding William E. Gilmore's financial interest in the Essex Press of Newark, which he kept secret from Edison, and the events leading to Gilmore's resignation as president and general manager of the National Phonograph Co. in July 1908. Among the correspondents are Frank L. Dyer, general counsel and (after July) president of the National Phonograph Co.; Leonard C. McChesney, manager of the Advertising Department; F. K. Dolbeer, manager of sales; and the accounting firm of Lybrand, Ross Bros. & Montgomery.

Approximately 60 percent of the documents have been selected. The items not selected include letters of inquiry, lists of advertisements, and documents that duplicate information in selected material.