Validity of Ergograph as Measurer of Work Capacity 25 



any discomfort and perform the usual amount of work. Practice 

 will enable such a reagent to make a larger number of contrac- 

 tions than he could otherwise make. Greater endurance means 

 the power of the nerve center to excite a muscle to perform a 

 certain work a greater number of times than it could before the 

 exercise to which it has been subjected. Of the four elements 

 into which practice gain has been analyzed, endurance is the one 

 which is acquired most slowly ; that is, it comes last. The left 

 hand of B. especially and the right hand of M. develop the 

 greater endurance. This is shown by the greater proportional 

 number of contractions made by these fingers. The number of 

 contractions has contributed more to the gain shown by these 

 fingers than the increase in height of contraction. The left hand 

 of M. began early to show great efficiency in coordination. The 

 movement always seemed easy and was never attended by feel- 

 ings of discomfort. The exhaustion point was reached without 

 warning signal. The onset of paralysis was most sudden, as 

 three or four contractions were usually all that could be made 

 after the finger once failed to reach the usual height. The right 

 hand of B. occupies an intermediate position. The early con- 

 tractions in an observation were rhythmical and unattended by 

 pain or discomfort. Long after the contractions began to fall 

 off in height and the hand and arm experienced uncomfortable 

 feelings, voluntary effort still availed somewhat to keep the finger 

 contracting, although the height grew steadily less. 



Our aim shall be to show how changes in these four different 

 directions have contributed toward the total amount of practice 

 gain shown by the reagents. 



Effect of rest periods upon practice gain and practice loss. — 

 The purpose of breaking the work up into a number of periods 

 was to determine the practice loss that would result from the 

 suspension of exercise for different periods of time. On one or 

 two occasions the rest period was enforced. An examination of 

 table I shows that during the first rest period an enormous 

 increase of power had taken place. A comparison of the records 

 for the four days previous to the rest with the first four imme- 

 diately after it gives these results. These are averages of four 

 records : 



103 



