EFFICIENCY AND FATIGUE 257 



works manager that the explanation lies in the fact 

 that the workers are determined to earn a certain 

 amount of wages, and so they knowingly work harder 

 when their hours of labour are cut down. Even if 

 this were the true explanation, it would surely be 

 worth while to make the reduction of hours, for the 

 running costs of the machinery would be reduced, 

 and the workers would obtain more leisure time; but 

 it is not the correct explanation. When a reduction 

 in the hours of work is introduced, nothing at all 

 happens to the hourly output for some weeks, and 

 then it gradually begins to mount up, but it takes 

 four months or more before it reaches a steady level 

 again, or until the workers have got into equilibrium 

 with their altered conditions of work. This altered 

 equilibrium is attained quite unconsciously by the 

 workers. When they are working excessively long 

 hours, such as twelve per day, they soon find that in 

 order to last out through the working week they must 

 go slow, otherwise they would soon become so fatigued 

 that they would have to take a holiday from work in 

 order to recuperate. Supposing their hours are re- 

 duced from twelve a day down to ten, they continue 

 to work at the same slow rate just at first, but they 

 gradually find by experience that they can work harder 

 and still harder without undue fatigue, and so they 

 slowly speed up their rate of production until they 

 reach a fresh maximum of output such as is just 

 compatible with the avoidance of over-fatigue. 



The relationship between hours of work and maxi- 

 mum efficiency is most easily explained by a hypo- 

 thetical example. Let us suppose that each vigorous 

 and healthy worker starts his day's work with 12 units 

 of energy, all of which he can put into active work if 

 he pleases without over-fatiguing himself, i.e. without 

 getting into a condition from which a good night's 



(C948) 1* 



