This letterbook covers the period January-February 1891. Most of the letters are by Alfred O. Tate. There is also correspondence by Edison, John F. Randolph, Charles J. Reed, and E. W. Thomas. 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 mining and ore milling, electric lighting, electric traction systems, and the Sims-Edison torpedo. There are also documents pertaining to experiments conducted at the West Orange laboratory for Edison-affiliated companies, including the Edison General Electric Co. and the North American Phonograph Co. Some of the letters pertain to patent matters and to Edison's personal finances; several refer to his trip to Schenectady, N.Y. to conduct experiments at the Edison Machine Works. There are also letters about Edison's family, including the death and funeral of his brother, William Pitt, and his efforts to secure a job for his cousin, Annie K. Doak. The spine is stamped "Letters" and is labeled "From Jan 20, 1891" The book contains 493 numbered pages and an index. Approximately 40 percent of the book has been selected.