This letterbook covers the period May-November 1905. Most of the correspondence is by Edison and John F. Randolph. There are also a few letters by Mina Miller Edison and others. Included is correspondence with field workers R. D. Casterline, John Morris, and Horace M. Wilson regarding Edison's search for cobalt ore, as well as numerous other letters pertaining to his interest in mines and ores. There are also letters discussing Edison's progress on his improved alkaline storage battery, his plans to reopen his factory in Glen Ridge, New Jersey, and the proposed organization of battery manufacturing companies in France and Germany. In addition, there are items relating to the business of the Edison Portland Cement Co. and to Edison's search for markets for his cement. Several letters addressed to Adolph Melzer deal with Edison's work on phonographs and with a lawsuit by the American Graphophone Co. against the National Phonograph Co. for the infringement of patents granted to Thomas H. Macdonald. There are also letters regarding the New York Phonograph Co.'s prolonged legal actions against the National Phonograph Co. Some letters refer to matters of employment and to supplies of chemicals and equipment for the West Orange laboratory. Among the items pertaining to family and personal matters are letters concerning Edison's interest in automobiles and his automobile trips; his property in Milan, Ohio; and the loan of an old phonograph for exhibition at the Florida State Fair.

The label on the front cover contains the following notation: "T.A. Edison - Letter Book. from May - 25 - 1905 to Nov. - 13 - 1905." There is an inscription on the spine with similar information. The spine is also stamped "5." The book contains 497 numbered pages and an index. Approximately 30 percent of the book has been selected.