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 letter in this folder is from May 3, 1917. It pertains to the development of a glass for telescopes or binoculars that would enable observers to locate enemy ships at night. A typewritten description of the night glass, with handwritten additions by an unidentified experimenter, is enclosed with the letter.