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 his folder are from February 1917. They pertain to Edison's efforts to produce an oil film that would smudge the periscopes of enemy submarines so that nothing could be seen. Related material can be found in Reports 7, 18 and 33.