380 THE HUMAN MOTOR 



At the Bethlehem Steel Works, before Mr. Taylor's advent, the 

 output was 12i tons per man per diem. Taylor increased this 

 to 47 tons per "man per day. Since 1881, while works manager 

 of the Midvale Steel Co., he had made an exhaustive study of the 

 relations between speed and time in human labour, f 1 ) His 

 experiments were conducted thus : He selected two of his best 

 labourers, strong, reliable, and intelligent men. He gave them 

 double pay during the period of the experiments, on the condition 

 that they would, throughout, work their hardest. He also warned 

 them that their output would be tested from time to time, and that 

 any deliberate " slacking " would entail dismissal. As a matter 

 of fact, the men did their best throughout the experiments. In 

 fact, Mr. Taylor adopted Coulomb's method as developed by 

 Chauveau. 



Under the above conditions the selected labourers carried out 

 various tasks. The time taken in each movement was registered 

 by a stop-watch, and other elements of labour were carefully 

 noted and recorded. 



It was found that the men could develop from ^ to & of a 

 horse-power according to the nature of the task on which they 

 were engaged, i.e., from 34,000 to 140,000 kilogrammetres per 

 liem. There did not appear to be any strict relation between 

 work and fatigue (see above, 125 and 130). 



At a later date M. Earth, a mathematician, took up the same 

 study. As the result of numerous observations he formulated 

 his " law connecting work and fatigue." 



It was found that the actual period during which the labourer 

 was sustaining a load should be approximately 43% of the working 

 day and that for the remaining 57% he should have no load. If 

 " half pigs," weighing 22 kg., were carried, the loaded period 

 might be increased to 58%. It was also found that there is a 

 limit to tiie load which can be carried continuously throughout 

 the day without fatigue. 



Chauveau and his pupils, by their experiments on the expendi- 

 ture of energy, had already arrived at similar conclusions to those 

 of Earth and Taylor. It is clear, however, that Taylor was chiefly 

 influenced by Coulomb. He observed, indeed, that " static 

 effort " caused muscular fatigue and necessitated intervals of 

 rest. He did not, however, frame any general formula for these 

 effects, as Chauveau did at a later date (vide 113). 



( l ) See Taylor's papers before the American Society of Mechanical 

 Engineers: A piece-rate System and Shop Management, and Scientific 

 Organisation of Workshops (loc. cit.). 



