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 one item in this folder is a letter from Edison to Daniels, dated February 23, 1918. It pertains to Edison's experiments on collision mats that would cover the hole in a merchant ship struck by an enemy torpedo and prevent it from sinking. Edison also refers to his work on the kite rudder (sea anchor) and expresses his opinion that these two inventions "should increase the difficulties of the Germans in sinking our boats. These are all attachments that cost little, require no change in ships and are easily operated."