474 RECORDS 



Dr. Woodworth stated that the fatigue movement may be 

 studied in reference to the loss in force, in accuracy, or in speed. 

 In each of these respects experiments show that a movement 

 may be continually repeated for hundreds and even thousands 

 of times with only a comparatively slight loss of efficiency. 

 The ergographic curve given by Mosso for force of movement 

 is to be abandoned absolutely as a true picture of the curve of 

 fatigue. This fact has been of late recognized in some able 

 articles by Treves, working in Mosso's own laboratory; but is 

 best brought out by the use of Cattell's spring ergograph. 

 One of the great causes of fatigue in force, and also in speed of 

 movement is the failure of the muscles to relax completely be- 

 tween successive contractions. If care is taken to secure this 

 relaxation, i ,000- 1 , 500 maximal ergographic contractions can be 

 made with a loss of only 10 per cent, of the initial force. From 

 the slowness of fatigue of various modes of voluntary move- 

 ment, the inference follows that the fatigue o nerve centres is 

 not rapid, as Mosso and Lombard have supposed, but slow in 

 progress. This view is confirmed by tests of prolonged, hard 

 and monotonous work of a mental kind. The quick and over- 

 mastering fatigue of common experience is not so much actual 

 inability and loss of function, as it is disinclination, resulting 

 from disagreeable sensations and emotions, and from impulses 

 to change. 



The third paper by Dr. Thorndike presented the results of 

 some experiments on the accuracy of discriminations of weight, 

 length, and area, by subjects who judged by the aid of mental 

 standards only. Within the limits chosen (40-1 2 gr., y^—12 ins., 

 20-60 sq. cm., and 2-12 sq. irs.), the accuracy of discrimina- 

 tion was found to decrease very slowly, very much more slowly 

 than Weber's law or even the law of the combination of errors 

 would allow. The theory proposed to account for this was that 

 our judgments of amount or of difference are of complex origin, 

 and may be made on various grounds. In so far as the ground 

 is an accurate mental standard, the sensations corresponding 

 to large amounts may be associated with the proper judgment 

 nearly or quite as readily as small amounts. In so far as the 



