91 Prof. Valentine on Mental and Physical Fatigue 



munition labourers seven days a week and overtime, as is done so 

 largely throughout the country, will in the long run produce any 

 more goods, and this is now being suspected and attended to- 

 But a fe\^ experiments at the beginning of the war might in the 

 course of a few weeks have settled this question definitely for us. 

 For example, four factories might be selected of similar type and 

 workmen withdrawn from similar localities, run them for a few 

 weeks seven days a week and overtime, and note the quantity of 

 work turned out. Then for a month continue factory A as before ; 

 in factory B drop Sunday work but continue overtime ; in factory 

 C drop overtime but work Sundays : in factory D drop both over- 

 time and Sundays. Keep exact record of production in all. This 

 of course would require co-ordination and Government control. 

 In conclusion, we have to admit the extreme difficulty of 

 experiment when we are concerned with the complex human mind 

 and body, and only by great patience and firm resolution to 

 reserve one's judgment until repeated tests under varying con- 

 ditions have been made, can we hope to attain reliable results. 

 But in judging the practical value of such work we must remember 

 that it has only been attempted within the last few years ; and as 

 Bergson said : " What might we not have seen accomplished if 

 the great crowd of investigators who have spent so many years in 

 experimenting in the physical sciences had been paralleled by a 

 group of workers, equal in number and devotion, experimenting 

 in the sphere of mind." 



