748 



THE POPULAR SCIENCE MONTHLY 



as Fig. 5, tliis pervades the whole record. Here the hand moves 

 to and fro, keeping time — not accurately at all, but in a general 

 way — Avith the strokes of the metronome. 



Fig. (i. — ■«H> Counting the Oscillations of a rExinLUJi. Time ot record, 45 seconds. 



To obtain similar results for a visual impression, a silently 

 swinging pendulum is used, the subject watching the oscillations 

 and counting them. The result is more frequently a movement 

 toward the pendulum, Fig. 6, but occasionally there appear peri- 

 odic movements due to the pen- 

 dulum. A very excellent instance 

 of the latter appears in Fig. 7. 



We may more closely approxi- 

 mate the ordinary experiment of 

 the muscle-reader by giving the 

 subject some object to hide, say 

 a knife, and then asking him to 

 place his hand upon the autom- 

 atograph and think intently of 

 the place of concealment. As be- 

 fore, there is a movement of the 

 hand, and on the basis of the gen- 

 eral direction of this movement 

 one may venture a prediction of 

 the direction in which the knife 

 lies. The results will show all 

 grades of success, from complete failure to an accurate localizing 

 of the object, but as good a record as Fig. 8 is not infrequent. In 

 this case the eyes are closed, and we have not the aid of the senses 



Fig. 7. — i)H» Counting Pendulum Oscilla- 

 tions. Time of record, 80 seconds. Shows 

 movement toward the pendulum at first, 

 and then movements synchronous with 

 its oscillations. 



Fig. 8.— w^ Thinking of a Hidden Object. Time, SO seconds. 



in maintaining a concentrated attention; moreover, the position 

 of the subject may not be suited to a ready movement in the 

 direction of the hidden object. 



A further interestiner mode of concentrating the attention con- 



