This notebook was used by Edison during the periods January-March 1914 and October 1916, partly at his West Orange laboratory and partly at his winter home in Fort Myers, Florida. The entries from 1914 pertain primarily to sound recording and amplification. Included are notes on modifications to musical instruments, phonograph horns, recording diaphragms, and reproducers, as well as notes on various chalk telephone and electromotograph devices to try in connection with recording. Also included are references to works by Herman von Helmholtz, Lord Rayleigh, John Tyndall, and other authorities on acoustics. One drawing involves studio arrangements for making kinetophone films and recordings. Another suggests making a hearing apparatus for the deaf. The entries from 1916 relate to Edison's research for the U.S. Navy during World War I. Included are notes that propose methods for detecting battleships and submarines, taking infrared photographs, and cooling machine guns. Other entries pertain to trench warfare, combating chemical warfare, bombs, air reconnaissance, inter-ship communication, and possible means for disabling submarine periscopes. The front cover is marked "Telephone Recording Navy." The pages are unnumbered. Approximately 135 pages have been used. Courtesy of Thomas Edison National Historical Park.