of Man, or Economic Coefficient of the Human Machine. 365 

 The present inquiry includes twenty-three experiments : 



G-ram O. Calories. 



The first set of four experiments on W.M. gave 1 3*071 



The second set of five experiments on E.. B. F. gave 1 3*401 



The third set of fourteen experiments on E. E. gave 1 3*265 



Mean 1 3*246 



Therefore it will be readily seen that 1 gram of oxygen will give 

 rise to more heat in a state of rest (1 : 4*000) than under exercise 

 (1 : 3*246), and it cannot be admitted that the same mean amount of 

 heat is produced by a given weight of oxygen absorbed in repose and 

 under exercise ; Him observed a similar occurrence. It may therefore 

 be concluded that the human body in the state of rest makes a more 

 efficient use of its oxygen than it does under exercise in the 'proportion 

 of about 4*000 : 3*246. 



The next, and perhaps most important subject for consideration, is 

 the efficiency or economic coefficient of the human machine. 



The efficiency of the body as a machine is the relation between the 

 theoretical heat corresponding to the work done* and the actual 

 amount of heat that the body requires to do this work. According to 

 this definition the result sought for in our inquiries was obtained by 

 dividing the theoretical amount of heat necessary for the work done in 

 each experiment by the heat given out during the work, less the 

 normal heat emitted in the same time plus the theoretical heat neces- 

 sary for the work. This statement can be expressed in the form of a 

 formula. 



If 



E = Efficiency of the human machine. 

 T = Theoretical calories necessary for the work done, 

 C = Heat emitted during the work, 

 c = Heat emitted in a state of rest, 

 then 



T 



E 



C-c 



The weight suspended from the end of the lever forming part of the 

 brake was 485 grams, and knowing the length of the lever (48*275 cm.) 

 it was easy to calculate that each turn of the wheel performed an 

 invariable amount of work = 1*471 kilogram-metres. 



Mechanical equivalent of heat multiplied by work done in kilogram-metres. 



