The one dated entry in this pocket notebook is from February 1917. The book was used by Edison, probably during the period February-April 1917, for notes pertaining primarily to war-related experiments. Included are entries relating to smokescreens that might enable Allied ships to conceal themselves from enemy submarines, as well as other camouflaging devices. Also included are experiments on sound detection devices and other means of locating submarines. There are also references to Edison's work on a "hydrogen detector" that would indicate the presence of dangerous gas in submarines. In addition, there are comments on torpedoes and other armaments, range finders, and the use of mirrors to blind machine gun operators. There are some notes on disc record production and on continuing efforts to cut down on the number of defects in the records. A few entries appear to be transcriptions of entries from PN-16-11-15.2. Among the employees who assisted Edison in his wartime research were Absalom M. Kennedy, William H. Knierim, and Benjamin Liebowitz. Employees mentioned in connection with disc records include William Walter Dinwiddie and George Werner. The flyleaf is inscribed "Started Feby 15." The pages are unnumbered. Approximately 150 pages have been used. Courtesy of Thomas Edison National Historical Park.