This letterbook covers the period December 1891-March 1892. Most of the letters are by Alfred O. Tate. There is also correspondence by Edison and Thomas Maguire. Many of the letters relate to the manufacture and marketing of phonographs and cylinder recordings and to legal and financial dealings among the various phonograph companies. There are several letters pertaining to Edison's loan of $3,500 to the Automatic Phonograph Exhibition Co. Other documents deal with mining and ore milling, electric light and power, and the kinetograph. Included also are letters about position openings at the West Orange laboratory and about the collection and storage of material at the Menlo Park laboratory. There are numerous letters, many addressed to Edison's attorney, Sherburne B. Eaton, regarding patent infringements and other patent matters. Beginning on page 89 is a three-page description of Edison's inventions for 1891. Beginning on page 189 is a five-page list of requirements for an electric railroad motor. The spine is stamped "Letters" and is labeled "From Dec. 31, 1891. To Mar. 9, 1892." The book contains 698 numbered pages and an index. Approximately 20 percent of the book has been selected. Related documents for this time period can be found in LB-051 and LB-053. Courtesy of Thomas Edison National Historical Park.