This notebook was used by John A. Hanley during May 1918-February 1919 for experimental notes on submarine detection. The entries deal primarily with the deployment, placement, rigging, and sensitivity of the detector. Also included are tests of listening devices for submarine torpedoes and experiments involving the "quick turning of ships." Some of the experiments were conducted aboard the USS Sachem and the harbor steamer Clio. The notes indicate that Hanley was reporting directly to Edison and that William A. Hayes was conducting related experiments during the same time. The front cover is labeled "Experiments. Edison Submarine Detector. No - 1. From, May 12-18, To, Feb 14-19 J. Hanley." The pages are unnumbered. Approximately 135 pages have been used. Courtesy of Thomas Edison National Historical Park.