The card indexes, prepared with thoroughness, showed the concerns that were working on military orders for foreign governments. It was ascertained that 35,000 concerns in the United States could manufacture war material, and the names, location and facilities of these plants were docketed. The Board pointed out, what afterwards became generally recognized, that the manufacture of munitions was a parts-making business. Parts made in Toledo, Ohio, must fit those made in Portland, Oregon, or Augusta, Georgia, and all these parts must fit each other to the hundredth part of an inch. Over 500 concerns manufactured parts of the Mark VI mine. When the Council of National Defense was established, it took over the data and organization, and requested the Naval Consulting Board to act as the official Board of Inventions for the country. After the experiments at Nahant, which followed the March meeting, in 1917, in company with Mr. Edison, Mr. William L. Saunders and others of the Consulting Board, I visited New London. We took a sea trip on a submarine-chaser equipped with listening devices. It was a matter of gratification to both civilians and naval men to witness personally the success of submarine detection, and to feel that their faith and experiments had been rewarded. Ship protection was the subject of constant study, and various methods--camouflage, armament, smoke-boxes, submarine and torpedo detection, plans to prevent and withstand attack and increase buoyancy--were studied by the Consulting Board. It was through that board that the naval research and experimental laboratory, now under way on the Potomac, below Washington, was established and the money provided through Congressional appropriation. Mr. Edison spent most of his time during the war--practically all of it--either on board the _Sachem_, which had been fitted up for his special use, or in his office in the Navy Department at Washington. I was in intimate touch with him. It was a revelation to go into his chart-room and talk to him about his study of the lanes of the sea; to see his maps studded with pins pointing out where sinkings were most frequent, and to obtain his advice as to the routing of ships to lessen the probability of attack. An authority on many other subjects, he learned much about troop transportation, the routing of merchant ships and their quick turn-around, and avoiding U-boats by changing routes. One of his most successful and yet least known of his experiments was in the detection of torpedoes. The Wizard of Menlo Park was most modest in his claims. To a lady, enthusiastic over what she called his inspiration, Mr. Edison is reported to have said, "Madam, it is not inspiration, but perspiration." In a letter to a sub-committee of the Senate, when some one had attributed the success in detecting submarines to Mr. Edison, he wrote: