22 THE NEW WORLD OF SCIENCE 



can penetrate water to a great distance. Soon after the loss 

 of the Titanic, an English inventor was granted patents for his 

 method of detecting objects above and below water by the echo 

 of beams of sound, ranging in frequency from 5,00x3 to 100,000 

 complete vibrations per second. The method was not carried 

 into practical effect at that time, but during the war the same 

 principle was applied by French and British men of science, 

 and important progress resulted. Before the end of the war 

 this device had been developed to such a degree as to enable 

 a destroyer to detect and run down a submarine more than a 

 mile away. 



After a two days' discussion of such methods by the Sub- 

 marine Conference, it became clear that a greatly intensified 

 attack on the problem of detection should be made. The Re- 

 search Council accordingly brought to Washington more than 

 forty leading physicists, and a second conference, of several 

 days' duration, was held with the foreign naval officers and 

 men of science. This resulted in the selection of several groups 

 of investigators to take up the problem at a point in its de- 

 velopment already attained here and abroad, and to continue 

 its study in cooperation with a special board appointed by the 

 Secretary of the Navy, on which the National Research Coun- 

 cil was represented. A more complete account of this work, 

 which involved the organization of special investigations in 

 laboratories in many parts of the country, may be found in 

 Chapter 3. 



An important extension of the duties of the National Re- 

 search Council occurred in July, 1917, when it was requested 

 by the Chief Signal Officer of the army to organize the Division 

 of Science and Research of the Signal Corps. A vice-chair- 

 man of the Council was commissioned in the army and placed 

 in charge of this Division, which was given offices in the build- 

 ing of the National Research Council in Washington, where the 

 Division undertook the solution of numerous problems of mili- 

 tary importance. Here it was a question both of the immediate 

 application of new scientific methods developed during the 



