772 THE POPULAR SCIENCE MONTHLY. 



furnish elements of greater probability and determine search in 

 that direction. To obtain an ideal curve for a uniform surface it 

 would be necessary to liberate the pigeon on a Dakota prairie or 

 in mid-ocean, where no break in the landscape is visible even 

 from an altitude of a thousand feet. It is not, however, diffi- 

 cult to find approximations to the 

 ideal in the widening circles and 

 the flights in different directions 

 to be seen in Figs. 1 to 4. 



It may seem to some that in 

 denying a "sense of direction" 

 and affirming a logic is like jump- 

 ing from the frying pan into the 



Fig. 11. 



Search-line of a shepherd doa. j. r_ j. * J.T. j c. j 



+ Starting point. B. Ball n tlllS P Olnt 1S that WG d find 



evidence for search-logic and no 



evidence for " direction-sense." And further, in the one case we 

 explain the phenomena by something fundamental in animal life, 

 which we do know something about; whereas on "sense-direc- 

 tion" grounds we are explaining the partially known by the 

 absolutely unknown. 



An instance of quite a different sort from the above stood in 

 the writer's mind as almost conclusive proof of sense-direction 

 powers for a number of years. It may be briefly stated as fol- 

 lows: 



A large Maltese tomcat once joined, on his own invitation, an 

 evening rowing party on one of the Wisconsin lakes. It was a 

 sultry summer night, as dark as a moonless night can be. Not a 

 breath of air was stirring. We rowed nearly due north, straight 

 out toward the middle of the lake, which is something over two 

 miles wide. For some time Tom purred and made himself gen- 

 erally agreeable from one end of the boat to the other ; but at 

 last he grew restless and extremely anxious to get home. He 

 would climb out to the end of the boat and, stretching his head 

 toward home, mew almost continuously. We amused ourselves 

 for some time by turning the boat slowly round and round, first 

 one way then the other, to see if we could throw Tom off his 

 bearings ; but all to no effect. Whether right side, left side, bow 

 or stern, Tom was always on the part of the boat nearest home, 

 and straining as far as he could in that direction. Fully a mile 

 from any shore, how could he tell which shore was which ? But 

 few lights were visible, the lake is thickly wooded, and the cot- 

 tages stand well back among the trees. Not one in the party 

 could recognize the lights of our own group of cottages. And no 

 one but myself and cat had any idea which way to go for home. 

 For my part, I had kept an eye out for the north star. But what 



