The Thomas A. Edison Papers Digital Edition

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 items in this folder are from November 1917-January 1918. A letter of November 21, 1917 from Edison to Sir Eric Geddes, First Lord of the British Admiralty, presents his plan for reducing the sinking of merchant ships traveling between Britain and France. A letter from Edison to Daniels, January 21, 1918, briefly discusses this plan along with a similar plan for the defense of the American coast (Report 47). As Edison recalled in his 1919 memoir, "the submarines could not do any damage if the [merchant] ships sailed in close to the shore, because a submarine has to have 60 ft. of water to do anything, and by mapping out the places having 7 fathoms of water, I devised a method which would defeat the submarines . . . After instructions were given to masters of vessels to stay within this 7 fathom area." This project is described on pp. 165-170 of Lloyd N. Scott's Naval Consulting Board of the United States. A transcription of Edison's letter to Geddes appears on pp. 167-170.

Edison's letter of January 21, 1918 also mentions his idea of observing enemy submarine periscopes from portholes three or four feet above the water line (Report 48) and his research indicating the futility of zigzagging as a method of submarine evasion for ships moving less than ten knots (Report 49). A letter to Daniels, written by Edison on the following day, encloses an extension of the strategic plan for coastal defense. That enclosure appears as map 45 in the appendix to Scott's Naval Consulting Board. Copies of the January 21 letter are filed with Reports 47-49. A typewritten notation on the bottom of these copies indicates that the letter was written during Edison's stay in Washington, D.C.