This collection consists primarily of letters exchanged between Edison and Secretary of the Navy Josephus Daniels, along with related correspondence. Many of the typewritten letters are accompanied by drafts in Edison's hand. The documents in this folder are from March-August 1917. They pertain to Edison's work on a "splash range finder"an apparatus that would determine the distance between an enemy ship and the splash of a projectile falling short. A photograph of Edison's invention is included in his report. Also included is correspondence with Lt. Giorgio Abetti of the Italian Military Commission, who was interested in having the Royal Italian Navy conduct further experiments on the splash range finder. In addition, there is a detailed description of the invention along with two blueprints submitted by Edison's personal assistant William H. Meadowcroft, as well as notes by experimenter Benjamin Liebowitz regarding a related inventiona "direct reading speed indicator" for determining the speed of distant ships. Courtesy of Charles Hummel.