20 THE NEW WORLD OF SCIENCE 



The members of the Committee sailed early in May, 1917, and 

 were most cordially welcomed and given information of great 

 value. 



The response of our foreign colleagues to our offer of co- 

 operation was immediate and effective. France sent to the 

 United States an able group of investigators, and both Eng- 

 land and Italy did likewise. The French members brought 

 with them a large collection of instruments and devices devel- 

 oped in France for military and naval purposes since the out- 

 break of the war, which was invaluable in connection with our 

 work. 



Just at this time the submarine danger was at its height. 

 Shipping to the amount of 900,000 tons was sunk by the Ger- 

 mans in April, 1917, and the British Government was ex- 

 tremely doubtful whether this menace, the most serious of 

 the war, could be overcome. As Admiral Sims has recently 

 pointed out, quick action was essential. The depth charge had 

 already been invented, and naval officers all agreed that if 

 the submarine could be definitely located it could be easily 

 destroyed. Thus the problem for the scientific investigator 

 was to devise a means of determining the exact position of a 

 submerged submarine. W r hile it was true that the results of 

 their researches might not be obtained and applied in time, it 

 was equally clear that no effort should be spared, even at that 

 late date, to devise the apparatus so urgently required. If the 

 vigorous action of the combined navies of the Allies should 

 succeed in alleviating the menace, without wholly overcoming 

 it, there might be time to develop a detection method which 

 would permit the finishing blow to be dealt. Fortunately for 

 the cause of the Allies, the convoy system, then regarded by 

 the masters of merchant ships as impracticable, was soon suc- 

 cessfully applied. But this outcome could not be foreseen, 

 and the men of science were in duty bound to contribute their 

 best efforts without delay. 



The National Research Council accordingly organized a con- 

 ference on the submarine problem in which the foreign repre- 



