Efficiency Methods
An Introduction to Scientific Management

FATIGUE-STUDY 97 his mathematical friend, Mr. C. G. Barth, who finally evolved a numerical expression which was as much of a “ law ” as Taylor wanted—a working hypothesis at least which lent itself to computation. It gave the percentage of the working-day during which the man’s muscles might be under strain. For very heavy work, such as handling pig-iron, the percentage was 43 ; if the work was lighter the percentage of time under load might be increased.1 Besides being applicable only to severe manual labour, this method of computation will seem generally very crude ; but it served its immediate purpose very well—except that the duration of continuous time for work before a suitable rest-time was given seems to have been at first left to the individual instructing the worker. We shall see that this is an important point. Since this original investigation by Taylor a good deal more attention has been paid to fatigue by both physiologists and psychologists; and there is now a good deal of valuable information accumulated, and accessible to all. But there is still something to be said for making a special study of the fatigue phenomena on the spot, and for each important industrial operation. Mr. Gilbreth points this out in his little book on Fatigue Study, in which he urges that managers should give some of their own time and energy and thought to first-hand observa- tions in their works, and should also endeavour to 1 *' Principles of Scientific Management,” p. 57 J see also