MEASUREMENTS 307 



active muscular groups. In reality the workman moves his arms 

 at the same time as his legs in many occupations. 



This is always the case in sports such as gymnastics, fencing 

 and boxing. In these the speed of the movements is, as a rule 

 far more important than the magnitude of the effort. 



Public speaking entails a certain amount of work, which 

 reaches high values in the orator, the actor and the singer. 



\ The work of speech has been measured by Marage f 1 ) from the 

 volume of air V expelled by the lungs and its pressure H in the 

 trachea. It is expressed by the product VH. But this estimation 

 gives only a fraction of the work performed by the orator, all 

 the muscular energy being excluded from it. The total work 

 done must apparently elude any experimental determination. 



235. Power of Man. This is estimated, in the case of con- 

 tinuous labour, or for a period of time t, by dividing the work 

 done by its duration expressed in seconds. This is the speed of 

 work. A scientific organisation of labour must assure that the 

 power of the workman is practically constant at each period, and 

 that it is not reduced by too rapid fatigue, due to bad mechanical 

 or physiological conditions. 



Marage (Journal de Physique, 1908, p. 298). 



