This notebook, which covers the period September-October 1917, was used by Edison aboard the USS Sachem in connection with his work for the U.S. Navy during World War I. Many of the entries relate to visibility at sea and to camouflage experiments conducted under various light and weather conditions. These include experiments with ships camouflaged by different canvas panels, as well as experiments with painted boards of different shades erected on shore and viewed from Long Island Sound. Also included are notes on devices to measure the amount of light reflected at the horizon. Additional entries pertain to smoke bombs and to the amplification of sound underwater for the detection of torpedoes. On page 170 is a list of projects in progress, along with Edison's approximation of the "percent finished." Among the projects listed are camouflage, periscope sighting, a Smoke bomb 3" gun, an underwater projectile gun, a Lyle gun smoke bomb, and "still" and "moving" torpedo detectors. Edison's notes indicate that Mina Miller Edison accompanied him aboard the Sachem and that the vessel cruised among Gardiners, Plum, Fishers, and other islands, using Greenport, Long Island, as a base of operations. The notes are continued in N-08-09-10.2. Outline drawings of two freighters have been inserted into the book. The front cover is marked "Front." The book contains 197 numbered pages, a few of which are blank. Courtesy of Thomas Edison National Historical Park.