142 THE HORSE OF MR. VON OSTEN 



the questioner bent forward, the horse would have been 

 able to tap any number desired. Since, however, only 

 the right foot was employed, the left one being used at 

 most for making a final tap, the number of taps had an 

 upper limit which was due to the fatigue of the animal. 

 This limit was about loo. That it was possible to ask 

 such questions as : " How many times is 100,000 con- 

 tained in 654321 ? ", and thus to give problems involving 

 millions, is perfectly clear. 



All wonderful feats of counting and computation which 

 were accomplished while thus experimenting with the 

 horse are to be accredited, not to the horse, but to 

 the questioner. If such is the case, they certainly cannot 

 be considered astonishing. Thus, when to the question, 

 " How many of the gentlemen present are wearing straw 

 hats ? " the horse answers correctly in accordance with 

 the wording of the question and omits the straw hat of 

 a lady, then Mr. von Osten is the guide. It is no wonder 

 that Hans never showed the slightest excitement when 

 confronted with difficult problems, nor that it apparently 

 took no time whatever to solve them. 



Hans, however, was also a faithful mirror of all the 

 errors of the questioner. Aside from mistakes due to 

 occasional interruptions on the part of visitors, these 

 errors had two sources: faulty computation and ina^ 

 quate concentratiprij^i. e., aside from arithmetical errors 

 ~oir the part of the questioner, were his premature or be- 

 lated movements. Since both of these factors might be 

 operative, the following three possibilities arise. 



(a) The questioner computes correctly but does not 

 move at the proper moment. Nearly all the errors which 

 had been accredited to the horse, were of this kind. 



A part of these errors had the appearance of being 



