TABLE 2. — Sound field intensity produced by "wampus" at 150 pounds water 



and 80 pounds air. 



TABLE 3. — Sound field intensity produced by "wampus' 



Eind no air. 



at 90 pounds water 



ELECTROMAGNETIC TRANSDUCER 



In order to fill in an untested part of the 

 range at the lower frequencies, the Bell 

 Telephone transducer lK-2 (fig. 28) was set 

 up in the pond at Leetown. The sound fre- 

 quencies it was capable of producing (200 to 

 10,000 c.p.s.) overlapped the range of the 

 electromagnetic water hammer tested in 1947 

 (67 to 3,000 c.p.s.). 



The familiar hum of the sine curve wave of 

 sound could be heard by everyone, up to about 

 9,000 c.p.s. Above that frequency the sound 

 escaping from the water was not audible to 

 most listeners due to the lack of intensity. 

 The trout did not respond to any sound fre- 

 quency within the range of the Bell transducer. 

 The tests were carried out in conformity with 



previous runs with other equipment and the 

 results are shown in figures 26 and 27. The 

 instrument was suspended at a distance of 

 2 feet from the fish in section No. 1, and with 

 the diaphragm 2 feet below the surface. Con- 

 tingency tests again showed significant dif- 

 ferences in distributions of fish of sound 

 tests and controls, but, as before, there is 

 nothing to indicate that the sound stimulus was 

 responsible. 



Except for casual tests with detonating 

 caps, the sound work with the U.S. Navy was 

 concluded. In a test of the effect of small 

 explosions upon trout, submerged fulminate 

 of n-iercury detonators were touched off in 

 succession at regular intervals of one to two 

 seconds. As before, the fish "started" at only 

 the first blast and did not swinn away as the 

 explosions continued. 



28 



