Thaddeus L. Bolton and Eleonora T. Miller 



of the work that the reagent does at each trial and hence may be 

 used to represent the actual work done. 



The present apparatus has followed the usual method in ergo- 

 graphs in employing the contraction of the middle finger, but, 

 contrary to the usual custom, it allows the use of both hands. 

 The hand is laid in pronation upon a board, and the contraction 

 of the finger is made downward over the end. The first and 

 third fingers are inserted in stalls and the hand, from the knuckles 

 back to the wrist, is held in a plaster-of-Paris cast which is 

 moulded over it. The arm itself is strapped down in two places. 

 The finger is inserted in a stall which can be adjusted both as 

 regards size and length of the finger. The point of attachment 

 for the weight is the same distance from the knuckle joint for 

 all persons, the adjustment for length being made at the end of 

 the finger. The finger is contracted downward, lifting a weight 

 which is caught at the limit of contraction by a ratchet formed 

 by a small steel ball that rolls on the grooved circumference of 

 a cylinder under a dog, and the finger allowed to relax freely. 

 The arrangements as regards the fixation of fingers and hands 

 are in general new. The reagent remains standing during the 

 test, occupying different sides of the instrument when the dif- 

 ferent hands are tested. Two views of the instrument and rea- 

 gent are given in Plate I. 



The weight used by one reagent was 6.84 kgs. and that by the 

 other reagent 3.58 kgs. The latter weight, however, had to be 

 increased toward the end of the experiment owing to the great 

 practice made by the reagent and to the limitations of the 

 apparatus. 



The experiment was performed by two reagents, a gentleman 

 and a lady, the instructor and assistant in psychology. The rea- 

 gents will be designated by the letters B. and M. Both B. and 

 M. have always enjoyed good health, except that B. has suffered 

 somewhat from pen-paralysis in the right hand. Both are vig- 

 orous and active and are accustomed to indulge in gymnastic 

 and outdoor exercise daily. B. had had considerable practice 

 previous to this time in work upon an ergograph similar in con- 

 struction to the one here used, and was not unpracticed at the 

 outset. The other reagent had. made a short series of observa- 



90 



