774 THE POPULAR SCIENCE MONTHLY. 



the slightest hesitation, toward the end of the boat nearest home. 

 To make doubly sure that vision was impossible, Tom was 

 wrapped up and gently held flat in the bottom of the boat. This 

 made no difference. Whether the boat was turned by a single 

 stroke, as on a pivot, or rowed slowly around in a circle, the result 

 was always the same. Tom went, without hesitation, invariably 

 to the end or side of the boat nearest home. 



Members of the party were blindfolded and required to guess 

 whether the boat was turned or allowed to stand still, or was 

 rowed in a straight line or in a circle ; and it was an even chance 

 whether they guessed right or wrong. Tom had a far better head 

 for direction than any of us. 



It was suggested that possibly a gentle current of air might be 

 serving Tom as a direction-constant. This, however, could hardly 

 have penetrated the shawl, and certainly not when in the bottom 

 of the boat. Still, might not such a current be conveying odors 

 imperceptible to man, but not to a cat ? None of our number 

 could feel the slightest breath of air on our faces, and even with 

 the moistened finger held above the head, it was impossible to 

 detect any flow of air. Might not then a wake of odor hanging 

 in the air over our course serve as the needed direction-constant ? 

 This could hardly be, since we had rowed about so much that 

 anything of the sort must have become thoroughly diffused. 



Sight, smell, and touch would thus seem to be inadequate to 

 explain the feat. Hearing still remains. But not a sound from 

 any shore broke the silence. No town or city was near to furnish 

 a roar, hum, or series of sounds of any sort. We could hear no 

 bands of music, nor even the occasional bark of a dog. For min- 

 utes at a time we could hear absolutely no sound. And yet, may 

 it not be that Tom heard every note some Tabby was making on 

 the shore a mile away ? If we were dealing with a sense as deli- 

 cate as this, further experiment was useless. We had no means 

 of stopping Tom's ears, and no microphone with which to explore 

 the darkness for sounds inaudible to our ears. 



The above explanation is open to serious objections. The chief 

 of these, aside from such acuteness of hearing, is the fact that at 

 no moment during the hour or more we were experimenting with 

 him did Tom show the least doubt as to his direction. The audi- 

 tory constant, therefore, must have been uninterrupted, and sup- 

 posing it to have been the mewing of some cat, or cats, we all 

 know what the possibilities are. At the time, the writer was 

 quite convinced to the contrary, but several years afterward an 

 incident occurred which threw the balance of probability strongly 

 toward the side of the auditory explanation. 



While hunting deer in Montana, I once lay on the top of a hill 

 watching a doe as she kept guard while her two fawns were feed- 



