This letterbook covers the period June-September 1916. Most of the correspondence is by Edison and William H. Meadowcroft. Included are letters pertaining to Edison's benzol absorbing plants and other chemical manufacturing interests. Other documents concern the technical and commercial development of Edison's phonograph business, his reading habits, and research at the West Orange laboratory. Among the correspondents are General Electric executive Charles A. Coffin, U.S. Secretary of the Navy Josephus Daniels, industrialists Harvey S. Firestone and Samuel Insull, economist Irving Fisher, and representatives of Mitsui & Co.

The spine is stamped "Letters" and is marked "T.A.E. From June 30 -1916- To Sept. 12 -1916- ." The number "51" also appears on the spine. The book contains 698 numbered pages and an index. Approximately 10 percent of the book has been selected.