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 invention—a "direct reading speed indicator" for determining the speed of distant ships.
[X128C28A], Letter from Thomas Alva Edison to Josephus Daniels, March 9th, 1917 1917-03-09
[X128C28B], Letter from Thomas Alva Edison to Josephus Daniels, May 1st, 1917 1917-05-01
[X128C28C], Technical Note, Benjamin Liebowitz, May 3rd, 1917 1917-05-03
[X128C28D], Memorandum, William Henry Meadowcroft, July 1917 1917-07-00
[X128C28D1], Technical Note, Benjamin Liebowitz, July 27th, 1917 1917-07-27
[X128C28E], Letter from Giorgio Abetti to William Henry Meadowcroft, July 18th, 1917 1917-07-18
[X128C28F], Letter from Thomas Alva Edison to Giorgio Abetti, July 26th, 1917 1917-07-26
[X128C28G], Letter from Giorgio Abetti to Thomas Alva Edison, August 2nd, 1917 1917-08-02
[X128C28H], Letter from Thomas Alva Edison to Giorgio Abetti, August 9th, 1917 1917-08-09