This letterbook covers the period October 1906-June 1907. Most of the correspondence is by Edison and John F. Randolph. There are also some letters by Mina Miller Edison. Many of the items relate to Edison's search for limestone, cobalt ore, and other ores. Also included are letters pertaining to the business of the Edison Portland Cement Co.; the operations of the cement works at Stewartsville, New Jersey; and Edison's progress on his poured concrete house. In addition, there are letters discussing Edison's work on his alkaline storage battery; the manufacture of batteries by Sigmund Bergmann in Berlin, Germany; and ore concentration operations in the Dunderland region of Norway, in connection with the Edison Ore Milling Syndicate, Ltd. Among the items pertaining to family and personal matters are letters concerning Edison's health; his membership in clubs and societies; the upkeep of his winter home at Fort Myers, Florida; and his donation of five hundred dollars to a public school in Milan, Ohio, for the purchase of scientific apparatus. Also included is a letter regarding a loan of one thousand dollars from Edison to his former associate Edward H. Johnson, as well as a letter by Edison reminiscing about his early years in Boston and New York.

The label on the front cover contains the following notation: "Thos. A. Edison. - Personal - Letter Book from October 1 - 1906 to July 1 - 1907." There is an inscription on the spine with similar information. The spine is also stamped "5." The book contains 502 numbered pages and an index. Approximately 10 percent of the book has been selected.