This notebook was used during July 1918. Most of the entries are by Edison, but there are also some by John A. Hanley. Many of these notes were made in the garage at Glenmont, Edison\'s home in Llewellyn Park, New Jersey, where he was working with Hanley, William A. Hayes, and probably James M. Burns on a series of experiments pertaining to the measurement and detection of sound under water in connection with work for the U.S. Navy during World War I. Included are tests with various devices used to pick up and amplify the sound of dripping or flowing water, possibly as a way of compensating for the interference experienced in listening to a sound detection device as it was towed behind a moving vessel. Among the components employed are long brass and rubber tubes, telephone receivers, and audions. The experiments are continued in N-18-07-11. The front cover is marked \"No 1\"" and \""Moore\"" and is labeled \""War.\"" The pages are unnumbered. Approximately 120 pages have been used."