■J bo POPULAR SCIENCE MONTHLY. 



with which the influence of practice and that of fatigue are lost. 

 Fatigue passes away, comparatively very quickly, while the gain 

 from practice, as already mentioned, is plainly demonstrable after 

 weeks and even months. Thus it happens that with intervals of 

 days or weeks each succeeding series of experiments begins with 

 a quickness in calculation which is much greater than the highest 

 achievement of the former experiment. The same takes place 

 likewise after the short breathing pauses, as long as these pauses 

 are sufficient to overcome in a measure the fatigue that has 

 begun. 



Since through the interpolation of pauses from work the other- 

 wise inevitably sinking efficiency is kept at a nearly even height, 

 the length of the periods of rest ought to be so adjusted that the 

 injurious effects of fatigue should never acquire a predominance 

 over the facility acquired by practice. If the experiment, how- 

 ever, is carried too far, the short pauses will no longer counter- 

 balance the effect of fatigue, and the capacity to work will become 

 null. For this reason the resting spells, if they are really to ac- 

 complish their purpose, should not only be much larger than they 

 are now in our schools, but should succeed one another at shorter 

 intervals and should be increased as the teaching is protracted. 



The picture which we have to compose on the basis of the ex- 

 periments under consideration is a gloomy one. While a quarter 

 of an hour of simple work is enough to develop the first signs of 

 fatigue in a twelve-year-old pupil, lessons of several hours' dura- 

 tion, interrupted only by a few short pauses, should soon lead to 

 complete mental exhaustion. The demand on attention is much 

 too long, the breathing spells are much too short, for healthy effi- 

 ciency to be maintained only remotely. 



The j)icture is, however, too darkly drawn. What I have 

 sketched could take place only if the schools attained what they 

 are striving for with all their means. Kind Nature has provided 

 a safety valve for the salvation of our growing youth, the value 

 of which can not be too highly estimated — inattention. Only by 

 effort, and only for a short time, can we force a measurable con- 

 centration of the full force of attention upon the solution of the 

 problem; care is therefore always taken in the school that the 

 time of the session shall not be regarded wholly as a time of 

 work. Burgerstein, indeed, thought that through the pauses he 

 introduced the relation between effort and relaxation might be 

 imitated in a regulated school hour. But these experiments seem 

 to me to show to a certainty that our children would necessarily 

 fall into mental disorder if they were really forced to work with 

 full attention for forty minutes in each school hour. That, in 

 fact, only a few are seriously injured by overwork in school is 

 due to those interruptions to study and those incidents in teach- 



