This undated notebook was possibly used during August 1917. All of the entries are by Edison and pertain to his work for the U.S. Navy during World War I. Included are notes on the way torpedoes work and how they sound, as well as Edison's reactions to newspaper reports of an oil tanker sunk by a German submarine. Additional entries consist of notes pertaining to poison gases, with references to the Watts dictionary of chemistry. The front cover is marked "No 2." The pages are unnumbered. Approximately 30 pages have been used. Courtesy of Thomas Edison National Historical Park.