THK QUESTION OF FATIGUE FROM THE ECONOMIC STANDPOINT. 321 



flow of material with the use of every minute of a man's work-time, 

 and closer supervision with an increased demand on the man to come 

 up to the standard. 



To isolate this factor of tuning up of efficiency, of the intensity of 

 work, it is only possible to compare the output and accident of single 

 factories ; whole states will include all varieties of efficiency. But in 

 comparing these single factories there are limitations, too, in the matter 

 of their output distribution. 



If in comparing an output curve in a less intensive with one in a 

 more intensive factory it was found that during a spell the latter did 

 not drop so fast as the former, it might be an indication of less fatigue 

 under the intensive system, but again it might be due to the greater 

 incentive to keep up speed. In short, the significance of the output 

 curve is, on this point, ambiguous. 



Turning to the accidents of single factories, however, we have a 

 chance of useful comparison in the distribution at the Ford (Table 

 XXL), Cadillac (Table XX.), and Northway (Table XXII.) and at 

 Hans Eenolds' (Table XVII.) Motor Companies. At each of these 

 engineering works efficiency has been carried to a very high pitch as 

 compared with Metal Working in general (Diagram II.) or Auto manu- 

 facture in general (Table IX. b). 



The distinctive feature of the accident curve in all these shops is 

 the higher rate of accident in the afternoon than in the morning. 

 Thus: 



Morning Afternoon 



Accident Rate per hour Accident Rate per hour 

 Hans Renolds . . 317 338 



Ford Motor Co. . • 222 235-5 



Cadillac „ . . 121 Ml 



Northway „ . .93 98 



On the other hand, in Metal Working generally (Diagram II.), if 

 we except the Massachusetts curve, which includes Foundries with 

 their regular afternoon casting, the afternoon rate of accident is lower 

 than the morning, and similarly of the Massachusetts ' Auto ' Industry 

 (Table XI.b, Col. 1). 



We may couple this contrast with that between the Iron and Steel 

 Making and all other naturally more persistent industries. Both bring 

 out the fact that scattered irregular pauses, be they due to the nature 

 of the material or to a hitch in factory action, all tend to relieve the 

 ' psycho-physique ' and to put a check to fatigue. Bogardus is very 

 right when he attributes present-day fatigue in the factory in great part 

 to ' unrelaxed tension. ' 



Further evidence of the fatiguing effect of intensity of work as apart 

 from its extension and duration in time may be sought by comparing 

 the accident rate in English industries in this present decade with 

 former times when the work was more ' extensive ' but less intense. 

 In this comparison, however, it is rather difficult to isolate the factor 

 of intensity; other factors have changed, too, of which the amount of 

 dangerous machinery and the guarding of that machinery are the 

 most important. Since these two most important factors affect accidents 



1915. ^ 



