THE APPLICATION OF THE SIXTH SENSE 

 TO SHIPS 



HAVING ascertained that the bat does possess a sixth sense, 

 and having discovered the organ that makes this sense pos- 

 sible, let us see now if we cannot accomplish the same thing 

 in a rough sort of a way on a large scale for use on steam- 

 ships at sea. 



The human ear has a range between the note that is given 

 off by a | -inch organ pipe and by one 32 feet long, but 

 the sound given off by a J-inch organ pipe is not audible to 

 us because the sound waves are too frequent ; there is 

 nothing in our ears that is able to respond to them, whereas 

 the note given off by a 33-foot organ pipe has not a sufficient 

 number of vibrations in a second to bring it within the 

 range of our ears. Low notes travel much farther than high 

 notes. The American bull-frog, which is about the size of a 

 man's fist, emits a deep bass note which can easily be heard 

 at a distance of two miles some writers say three miles. 



It is known that whales are able to communicate with 

 each other over vast distances by some species of low 

 bellowing, but the note given off is too low to have any 

 effect on the human ear. 



At the age of thirteen, I discovered that the common mouse 

 is quite unable to hear the voice of a man, but it is able to 

 hear the voice of a woman, in which the number of vibrations 

 per second is about four times as great as in a man's voice. 



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