This folder contains correspondence, financial documents, and technical notes relating to research conducted by Edison on various projects for the U.S. Navy and U.S. Army through October 1919. Some of the documents pertain to an automatic star gauge developed to measure cannon bores. Other letters, exchanged with the office of the Chief of Ordnance, concern an inquiry about the authorization of payments to Edison. At the end of the folder is a statement of the total amount billed to the Army and Navy for each research project since the beginning of the war, along with lists of code designations and staff who worked on war-related research. The statement indicates that approximately $107,000 of the $238,000 grand total was billed for submarine detectors.
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 Edison's personal assistant William H. Meadowcroft and by Richard W. Kellow of Thomas A. Edison, Personal. Courtesy of Thomas Edison National Historical Park.