particular the General Electric Company, the Western Electric Company, and the Submarine Signal Company had taken up the matter at their own expense; each had a research department and an experimental station where a large amount of preliminary work had been done. Soon a special board was created at Washington to study detection devices, to which each of these companies was invited to send a representative; the board eventually took up its headquarters at New London, and was assisted in this work by some of the leading physicists of our universities. All through the summer and autumn of 1917 these men kept industriously at their task; to such good purpose did they labour that by October of that year several devices had been invented which seemed to promise satisfactory results. In beginning their labours they had one great advantage : European scientists had already made considerable progress in this work, and the results of their studies were at once placed at our disposal by the Allied Admiralties. Moreover, these Admiralties sent over several of their experts to co-operate with us. About that time Captain Richard H. Leigh, U.S.N., who had been assigned to command the subchaser detachments abroad, was sent to Europe to confer with the Allied Admiralties, and to test, in actual operations against submarines, the detection devices which had been developed at the New London station. Captain Leigh, who after the armistice became my chief-of-staff at London, was not only one of our ablest officers, but he had long been interested in detection devices, and was a great believer in their possibilities.
The British, of course, received Captain Leigh cordially and gave him the necessary facilities for experimenting with his devices, but it was quite apparent that they did not anticipate any very satisfactory results. The trouble was that so many inventors had presented new ideas which had proved useless that we were all more or less doubtful. They had been attempting to solve this problem ever since the beginning of the war ; British inventors had developed several promising hydrophones, but these instruments had not proved efficient in locating a submarine with sufficient accuracy to enable us to destroy it with depth charges. These disappointments quite naturally created an atmosphere of scepticism which, however, did
