This letterbook covers the period February-April l89l. Most of the letters are by Alfred O. Tate. There is also correspondence by Edison, Thomas Maguire, and John F. Randolph. Many of the letters relate to the manufacture and marketing of the phonograph and to legal and financial dealings among the various phonograph companies. Some of the legal correspondence concerns the suit brought against Edison and the Edison Phonograph Works by the Edison Phonograph Toy Manufacturing Co. Other letters relate to foreign patents, improvements in the incandescent lamp, mining and ore milling, and electric traction systems. There are also letters dealing with Edison's personal finances, including his investment in the local illuminating company at Sunbury, Pennsylvania; his financial relations with Jesse Lippincott and Harry M. Livor; and his transfer of ownership of the Edison home at Glenmont to his wife, Mina. There are several letters pertaining to billing arrangements for experiments conducted at the West Orange laboratory for the Edison General Electric Co. There is also correspondence regarding alterations and improvements in the laboratory. The front cover is marked "General Letter Book." The book contains 497 numbered pages and an index. Approximately 30 percent of the book has been selected.