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 two letters in this folder are from March 1917. They pertain to a device developed by Edison for use in observing periscopes and other small objects from ships, which would remove most of the glare caused by bright sunlight. A photograph of the invention is included with Edison's letter.