PRACTICAL PHASES OF MENTAL FATIGUE. 519 



touch, and the other senses, show that there is lessened ability in 

 conditions of fatigue; * and this is accounted for probably by the 

 waning power of attention. The mind can be held to one thing, 

 excluding irrelevant matters. This phenomenon is further illus- 

 trated in the following simple experiment: The pupils in a large 

 graded school in Buffalo, N. Y., were required upon three succes- 

 sive days, at half past nine o'clock and again at half past eleven in 

 the morning, to trisect a line three inches long. The results, cal- 

 culated for one hundred and fifty children, show that on the aver- 

 age they were several millimetres nearer correct in the morning 

 trisections than in those just before the midday recess.f It seems 

 that this test measured the degree of attention which pupils were 

 able to exert at different hours during the day, and it confirmed 

 what must in a way be known to every one that a day's work in 

 school reduces the energy of attention. Doubtless every instructor 

 has remarked how much more difficult it is at half past eleven than 

 at ten to hold the thoughts of students to the subject in hand, and 

 if recitations in intricate studies occur late in the forenoon, progress 

 will be slower and more errors will be made, simply because pupils 

 are unable to attend so critically. 



The significance of this latter effect of fatigue must be appar- 

 ent when it is realized that attention is at the basis of all the 

 intellectual processes. If one can not attend vitally, he can not 

 perceive readily or accurately; he will be unable to recall fully or 

 speedily what has formerly been thoroughly mastered; and, most 

 serious of all, he can not so well compare objects or ideas to discover 

 their relationships that is, he is not so ready or accurate in reason. 

 In fatigue, then, one really becomes stupid. Suppose a fatigued 

 pupil in school working over his spelling lesson, for instance; he 

 will be liable to make errors both in copying from the board and 

 in reproducing what he already knows. In recitations in history, 

 memory will be halting; what has apparently been made secure 

 some time before now seems to be out of reach. In those studies 

 requiring reflection, as arithmetic, grammar, geography, and the 

 like, the reasoner will be unable to hold his thoughts continu- 

 ously to the matters under consideration, and so will be unable to 

 detect relationships between them readily and accurately. When 

 one considers, in view of what is here set forth, that many persons, 

 adults as well as students, are for one cause or another in a constant 



* See Educational Review, op. cit. ; Galton, Journal of the Anthropological Institute, 

 1888, pp. 153 et seq. 



f Since this article was written extensive investigations on school-room fatigue have 

 been made in the schools of Madison, Wis., under the writer's direction, and the general 

 principles here mentioned have been corroborated. 



