FORCING INTELLIGENCE 85 



equivalents of ball and socket joints at two points, 

 thereby admitting vertical, horizontal, and inter- 

 mediate movements. At the other end of each of 

 these levers is a beautifully complex organic instru- 

 ment called the hand, possessing in addition to the 

 possibilities of changes in position attained by 

 connection with the arms those derived from its 

 own infinitely mobile mode of attachment. At the 

 extreme outer end of each hand are the fingers, 

 triple jointed, separate compound levers, each joint 

 about one-third the length of the hand, the hands 

 being about one-half the length of each of the two 

 sections of the arm. These varying lengths have 

 their advantages. The finger joints are admirably 

 adapted to familiarity with relations between ob- 

 jects or parts of objects of small size. The hands 

 answer the same purpose for larger ones, and the 

 arms for still larger, until proportions are reached 

 which can only be estimated by the locomotion of 

 the whole body. It is obvious that by such an 

 apparatus magnitudes both smaller and greater 

 than those which are measurable by contact can 

 be brought within the range of consciousness. 



In addition to the great diversity of movements 

 made possible by arms and hands, the fingers can 

 independently move in the horizontal and vertical 

 direction and in compounds of these two. The 

 distance between the outer ends of the fingers can 

 at will be made to vary from about six inches apart 

 to actual contact. The angular direction of each 



