734 



SCIENCE 



[N. S. Vol. XLIV. No. 1143 



tigue are those that are characterized by 

 great muscular effort; unusual quickness 

 or complexity of muscular action; single 

 acts, however simple, that are monoton- 

 ously repeated over long intervals of time ; 

 constant strain in attention or bodily posi- 

 tion; and those in which the work is car- 

 ried on in excessively crowded places, in 

 excessive heat and humidity, in the midst 

 of excessive noise, or under other unfavor- 

 able environmental conditions. 



While different occupations thus differ 

 in fatiguing power, not only in themselves, 

 but in accordance with the external condi- 

 tions under which the work is performed, 

 there exist also great differences among hu- 

 man being's in their susceptibility to fatigue 

 from a given occupation. This also is par- 

 alleled by individual muscles in a familiar 

 laboratory experiment: Homologous mus- 

 cles from different experimental animals or 

 even from opposite limbs of the same ani- 

 mal, when stimulated at the same rate and 

 lifting equal loads, do not usually perform 

 the same amount of work. In industrial 

 work every observant foreman who knows 

 his men recognizes their individual differ- 

 ences in working power. 



Neither the fatiguing effects of the mani- 

 fold varieties of labor nor the susceptibili- 

 ties of different laborers to fatigue have 

 been studied with the degree and the care 

 that the subjects demand, and with such 

 paucity of knowledge it seems hardly pos- 

 sible at present to attempt to answer the 

 question whether the reduction of the 

 working-period to eight hours is a physio- 

 logical necessity. The universality of the 

 beneficial effects of such a reduction, how- 

 ever, argues strongly in favor of an affirma- 

 tive reply. There has been no more clear- 

 sighted observer and more logically ana- 

 lytic thinker on this topic than the late 

 Professor Abbe, of Jena, in whom the 

 breadth of scholarly culture was combined 

 with a keen sense of efficient business or- 



ganization. Ten years ago, after carefully 

 analyzing the results of the reduction of 

 the working-day in the Zeiss Optical "Works 

 and elsewhere, and considering the general 

 condition of German industries, with their 

 then prevailing long, and English indus- 

 tries, with their short, working-day, Abbe 

 came to the conclusion that by far the ma- 

 jority of industrial workers do not reach 

 their optimum in nine, and do not surpass 

 it in eight, hours. With him the shorter 

 day represents the physiological ideal and 

 the goal for which industries should strive. 

 I am disposed to agree in general with 

 Professor Abbe's conclusion for the pres- 

 ent day. But it is evident, I think, that 

 such a conclusion offers merely a tempo- 

 rary expedient. The establishment of a 

 rigid and universal eight-hour system 

 would probably prove not to be the best for 

 all industries and for all individuals. In 

 order to enable the wisest decision of the 

 question to be made there is needed not 

 mere opinions — not the opinions of employ- 

 ers, however broad-minded or narrow- 

 minded; or of laborers, however indus- 

 trious or indolent ; or of labor leaders, how- 

 ever generous or selfish their ambitions; or 

 of the laity, however philanthropic their 

 motives ; or of statesmen, whether they are 

 impelled by a high idealism or by practical 

 politics ; but a rigidly scientific study of the 

 question, through the medium of labora- 

 tory tests, of the physiological effects of 

 different occupations and the physiological 

 capacities of different laborers and a re- 

 sultant classification, on a physiological 

 basis, of work and workers. Such a study 

 is not impossible, and it would afford the 

 only basis for a rational and really intelli- 

 gent solution of the problem. It would 

 doubtless lead to the establishment of no 

 rigid, but an elastic system, in which the 

 work would be adapted to the worker, and 

 the worker to the work. In one industry 

 the duration of labor might be eight hours, 



