CHAPTER II 



EXPERIMENTS AND OBSERVATIONS 



A. Experimental Conditions 



The observations on the horse under ordinary condi- 

 tions would have been quite insufficient for arriving at a 

 decision as to the tenability of the several possible ex- 

 planations. For this purpose experimentation with con- 

 trolled conditions was necessary. 



It was necessary, first, that the place in which the 

 experiments were performed should be guarded against 

 sources of error and interruptions. Several diffi- 

 culties stood in the way of the removal of the horse to a 

 more convenient place. Therefore, a large canvas tent 

 was erected within the courtyard of Mr. von Osten. This 

 afforded the necessary isolation without hindering the 

 free movements of the horse. After the essential part of 

 the experiment had been completed and the problem had 

 been practically solved, experimentation was sometimes 

 conducted in the open courtyard. A number of the ex- 

 periments were also performed in the horse's stall. 



The choice of proper persons to experiment with the 

 horse required careful consideration. In so far as ob- 

 servations were to be made upon the questioner, Mr. 

 von Osten was of course indispensable. But to obviate 

 every objection he, as well as Mr. Schillings, had to be 

 excluded from the greater part of the experiments, and 



30 



