64 THE HORSE OF MR. VON OSTEN 



Schillings' attempts to disturb the horse and how naturally 

 he might conclude that Hans was not influenced by visual 

 signs. Mr. Schillings simply did not know which signs 

 were effective. 



While the horse could thus be interrupted in the process 

 of tapping by movements which were executed at the 

 level of the questioner's head, yet movements below this 

 level had the opposite effect. If Hans showed that he 

 was about to cease tapping before it was desired, it was 

 possible to cause him to continue by simply bending for- 

 ward a trifle more. The greater angle at which the 

 questioner's trunk was now inclined caused the horse to 

 increase the rate of tapping. The rule may be stated 

 thus: The greater the angle at which the body inclined 

 forward, the greater the horse's rate of tapping, and vice 

 versa. It was noticeable that whenever Mr. von Osten 

 asked for a relatively large number — in which case he 

 always bent farther forward than in the case of smaller 

 numbers — Hans would immediately begin to tap very 

 swiftly. Not being entirely satisfied with these observa- 

 tions, the following more exact measurements were taken. 

 I asked the horse to tap 20. From i to 10 I held my body 

 at a certain constant angle, at 10 I suddenly bent farther 

 forward and retained this posture until 20 had been 

 reached. If there existed a relationship between the angle 

 of inclination and the rate of tapping, then the time for 

 the last ten taps ought to be less than for the first ten. 

 Of 34 such tests 31 were sucessful. The following are 

 two specimen series. 



The first series consisted of ten tests of 15 taps each. 

 In all cases my head was bent at an angle of 30° to the 

 axis of the trunk, but I constantly changed the angle of 

 inclination of the trunk. It was not possible to measure 



