I.— PHYSIOLOGY. 



169 



efficiency in a mechanical sense. In an experiment with M.A.M., who, 

 in the postabsorptive state, rode on a bicycle ergometer for nearly four 

 and a-half hours until on the verge of collapse, doing 208,000 kilo- 

 grammetres of external work during the time, the metabolism was 

 deteiTTiined six times during the riding period with the following 

 result: — 



Table IT. 



I 



It will be noted, as might be expected, that there is some slowing 

 of the rate at which the work is done, but the diminution in the net 

 efficiency, in spite of the fact that the subject admitted he was com- 

 pletely done at the conclusion of the last determination, is not striking. 



In other experiments where the type of muscle activity used v/as 

 marcliing, little apparent effect on the metabolic cost was noted until 

 extraneous muscle activity was introduced in the form of staggering 

 as the result of exhaustion. 



Obviously, then, the capacity to can-y on is limited by the genesis 

 of fatigue. But it is equally obvious in practice that a man may b© 

 engaged in strenuous labour for many hours without acute signs of 

 impending exhaustion. How is this condition attained? There are 

 at least four factors which, to my mind, play predominant roles in the 

 attainment of maximum efficiency — viz., the rate of the performance 

 of work, the amount of rest offered or taken by the subject, the rhythm 

 with which the work is performed, and the work habits developed by 

 the worker. Although I shall attempt to' examine each of these factors 

 separately, it is not to be inferred that they can really be considered 

 as independent phenomena. As a matter of fact, they are all intimately 

 related, and usually merge into one another. 



Of these four factors probably most attention has been devoted 

 to the rate or speed at which work is carried out. The glorification of 

 that much misused half-truth, ' Time is money,' is responsible for much 

 false physiology. Farmer, in a recent report to the Industrial Fatigue 

 Board, laid, I think, the correct stress on the relation of speed to 

 general industrial efficiency when he wrote : ' No movement can be com- 

 pared with another and said to be better than it merely on account 

 of its speed; it should only be compared in respect to ease and final 

 result.' This is a good answer to those w-ho believe that maximum 

 efficiency can be best obtained by mere speeding up. Goldmark also 

 stresses this aspect of the question. She writes: 'Now just in pro- 

 portion as fliis function of speed is developed, subject to the capacities 



