This letterbook covers the period September-November 1915. Most of the correspondence is by Edison and William H. Meadowcroft. Numerous items relate to the technical and commercial development of phonographs and recordings. There is also correspondence pertaining to Edisonís benzol absorbing plants and other chemical manufacturing interests, as well as business conditions during World War I. A few documents concern the sale of toluol to the British government. There are also letters regarding Condensite, the phenolic resin varnish developed by Jonas Walter Aylsworth and used to coat phonograph records, along with correspondence about Edisonís cement business. The correspondents include motion picture executive J. Stuart Blackton, investment banker Clarence Dillon, and representatives of Mitsui & Co.
The spine is stamped "Letters" and is marked "T.A.E. From Sept. 25 1915 to Nov. 5 1915." The number "45" also appears on the spine. The book contains 700 numbered pages and an index. Approximately 5 percent of the book has been selected. Courtesy of Thomas Edison National Historical Park.