This pocket notebook, which covers the period September-October 1918, was used by Edison concurrently with PN-18-09-10.1. The entries in this book pertain primarily to war-related experiments conducted in the garage at Glenmont, Edison's home in Llewellyn Park, New Jersey; at the U.S. Naval Experiment Station in New London, Connecticut; and possibly at other locations on Long Island Sound. Included are notes on sound detection devices and other means of locating submarines. Also included are notes on camouflaging, poison gases, smoke generation, and the penetration of machine gun bullets. In addition, there are comments about the "possible source of noises on Cargo boats" and "possible means of detecting German 2 Knot noiseless subs," along with other remarks about underwater acoustics. A few of the entries relate to the production of disc records. Pinned into the front of the book is a letter of introduction from Secretary of the Navy Josephus Daniels, addressed to the "Commandants of Navy Yards." Among the employees mentioned in the book are experimenters James M. Burns, John A. Hanley, William A. Hayes, and Paul D. Payne, as well as Edison's assistants Charles B. Hanford and William H. Meadowcroft. The front cover is marked "War." The pages are unnumbered. Approximately 150 pages have been used.