LOCOMOTION 385 



Katzenstein, f 1 ) who was the first to make any reliable measure- 

 ments of the expenditure of energy, obtained a result of 8 small 

 calories per kilogrammetre. Chauveau ( 2 ) showed that the 

 ascent under load increased the expenditure of energy, while an 

 increased speed of walking decreased the expenditure ( 115), 

 and that it generally varied between 9 and 12 calories. It is, 

 however, to be observed that Chauveau 's experiments were not 

 sufficiently prolonged. 



Zuntz and Schumburg ( 3 ) obtained, as an average result, 7J 

 small calories. Frentzel and Reach ( 4 ) obtained a similar result. 

 Laulanie, by measuring the expenditure of energy during a 

 period of 75 seconds, obtained results varying from 9-6 to 15 

 small calories according to the load.( 5 ) 



The experiments of the above-quoted authorities were confined 

 to loads of from 10 to 30 kilogrammes and speeds of from -04 to 

 07 metres per second. Also the duration of each trial did not 

 exceed two or three minutes, or less in the experiments of Chau- 

 veau and Laulanie. 



The writer's investigations have, however, been directed to 

 establishing the conditions for continuous work. He took the 

 case of men ascending and descending a stairway of which the 

 steps were a little more than -16 m. high, while the inclination of 

 the stairway was steep. The loads varied from 40 to 60 kilo- 

 grammes, and consisted of sacks of beans, which the bearers 

 carried on their shoulders or necks. The speed was left to the 

 discretion of the bearers, but, when adopted, was kept constant 

 to the end of the trial. The rests were of two or three minutes. 

 The subjects of the experiments were strong and healthy 

 labourers, of ages varying from 20 to 40 years, and they did their 

 best. The average speed varied from -07 to T metres per second. ( 6 ) 



A descent followed each ascent. In this case the expenditure 

 of energy is 1-52 times that of a simple ascent ( 140), hence the 



expenditure of energy in the ascent alone isy^o of that of the 



complete trip, up and down. The following table gives a sum- 

 mary of the writer's observations : 



(!) Katzenstein (Pfluger's Arch., vol. xlix., p. 330, 1891). 



( 2 ) Chauveau (Comptes Rendus Sciences, vol. cxxxii., p. 194, 1901). 



( 8 ) Zuntz and Schumburg, Physiol. des Marsches, p. 277, 1901. 



( 4 ) Frentzel and Reach (Pfluger's Arch., vol. Ixxxiii., p. 441, 1901). 



( 5 ) Laulanie, Trait 6 de Physiol., p. 792, 1905. 



( 6 ) Jules Amar, Le Rendement, pp. 68-71. 



