This letterbook covers the period March-April 1890. Most of the letters are by Alfred O. Tate. There is also correspondence by Edison and Charles Batchelor. Many of the documents relate to the manufacture and marketing of the phonograph and talking doll. Included are letters about the coin-operated phonograph, the operations of the recently organized Edison United Phonograph Co., and a plan to record the voice of British Prime Minister William E. Gladstone. Other letters concern the phonoplex system, mining and ore milling, electric lighting, and the Edison-Lalande battery. Some of the letters pertain to the stock transactions of the various phonograph and electric light companies. Included also are letters to the firm of Dyer & Seely regarding patent applications and other patent matters. The book contains 499 numbered pages and an index. Approximately 40 percent of the book has been selected.