2 HAYES— DETECTION OF SUBMARINES. 



(a) Drifting— K-Tube. 



(b) Towing— OS, OV, and OK Tubes. 



(c) On Board— X, Y, and Delta Tubes. 



III. U. S. Naval Experimental Station — Multi-Unit Devices, 

 (i) M-B Tube. 



(2) Double M-F Tube. 



(3) Acoustical M-V Tube. 



(4) Electrical M-V Tube. 



(a) Towing — U-3 Tube. 



(b) On Board— M-V-62. 



11. Results accomplished by hydrophone installations during war. 



12. Possibilities of these instruments in times of peace. 



Introduction. 



The development of submarine detectors in this country started 

 shortly after the United States entered the war. In April, 191 /, 

 the Submarine Signal Company, General Electric Company, and the 

 Western Electric Company combined for the study of submarine 

 detector apparatus and started a station at Nahant, Massachusetts. 

 A foreign commission from France and Great Britain visited the 

 United States in June, 1917, and laid before those most interested 

 all the knowledge of submarine detection at that time in the hands 

 of the French and the British. As a result of this visit, the United 

 States Naval Experimental Station was started at New London, 

 Connecticut, under the control of the United States Navy, and sev- 

 eral physicists and engineers from different parts of the country 

 were called together to carry on the research and development work 

 at this station under the direction of the Special Board on Anti- 

 submarine Devices. 



In the following paper no attempt has been made to give credit 

 to individuals, but the developments brought about at the Naval Ex- 

 perimental Station and at the Nahant Station have been carefully 

 stated in the hopes that proper credit may be given to each group of 

 experimenters and in order that the excellent results accomplished 

 by the United States Navy in this comparatively new field may be 

 made known to the public. 



General Methods. 



The presence of a body beyond our reach can be detected by in- 

 tercepting some form of energy radiating from the body or through 



