This folder contains correspondence, financial documents, and technical notes relating to research on various projects conducted by Edison for the U.S. Navy and U.S. Army during 1918. The bills submitted regularly by Edison show that his main project for the Army was the destruction of wire entanglements; for the Navy, submarine detection and strategy and the phonograph range finder. There are also letters to and from the Office of the Chief Signal Officer dealing with experiments in field communications. A communication from Richard W. Kellow, secretary of Thomas A. Edison, Personal, indicates that the billing process was haphazard due to secrecy concerns and the rapidly changing nature of the work. At the end of the folder is a list of experiments from March 1917 to November 1918, with the laboratory order number, description, and cost of each.
Approximately 40 percent of the documents have been selected, including all of the substantive correspondence, a small number of technical notes directly relating to Edison, and about half of the financial material. Unselected documents include calculations and drawings by other experimenters (most of whom are unidentified), various printed tables and specifications, payment forms issued by the Army and Navy in connection with Edison's expense claims, and correspondence about minor accounting questions handled by Kellow and by Edison's personal assistant, William H. Meadowcroft. Courtesy of Thomas Edison National Historical Park.