This letterbook covers the period February-March 1913. Most of the correspondence is by Edison and William H. Meadowcroft. Included are letters addressed to physicist Michael I. Pupin and to Edison's European associates Paul H. Cromelin, Thomas Graf, and G. Croyden Marks. Many of the items relate to the commercial and technical development of Edison's phonograph and motion picture businesses, including the introduction of the disc phonograph and the kinetophone (motion pictures with sound). Other letters discuss the use of Edison's alkaline storage battery in miners' safety lamps, for which he won the Rathenau Medal in 1912, as well as its applications in electric vehicles and country house lighting. Also included is correspondence regarding Edison's cement and ore milling business, the procurement of Ortho-Cresol from Germany, and foreign markets for the kinetophone. Additional letters pertain to books read by Edison or added to his library, visitors to the laboratory, Edison's membership in organizations, and the inventor's donations to charities, including a contribution to the Balkan War Relief Fund.
The front cover is marked "T. A. E. From, Jan. 8, 1913. To, March, 6, 1913." The spine is marked with similar information, along with the number "31." The book contains 698 numbered pages and an index. Approximately 10 percent of the book has been selected. Courtesy of Thomas Edison National Historical Park.