158 BENEDICT— THE INFLUENCE OF [February 4, 



all of athletic build, the heat production is somewhat larger than 

 would be expected from men in sedentary occupations and you will 

 remember in the mental tests, the heat production per hour averaged 

 99 calories. The average here is a little higher and is readily 

 accounted for by the fact that the men were muscular. In the 

 second column is recorded the heat production per hour during the 

 period when the subjects were engaged in severe muscular work on 

 the bicycle ergometer. Here the differences between the different 

 subjects are very great. The lowest heat production was in the 

 case of B.F.D. 318 calories, and the highest nearly twice as great, 

 namely, 619 calories by N.B. While at first sight, it would appear 

 that there was a very marked difference in the work or efficiency 

 from these figures given in this column, it is necessary for us first 

 to find out how much of this enormous heat production was actu- 

 ally converted into mechanical work, and we find that in the third 

 column there were very large differences in the amounts of work 

 accomplished by these men. These differences can be explained 

 on two grounds, first, the rate of revolution of the pedals was 

 different, and second, the degree of resistance in the electric brake 

 was very different. It is interesting to note that the first three men 

 during work gave off about 330 calories per hour and accomplished 

 about 46 to 47 calories of effective work, thereby showing very 

 little difference in either the total heat production or in the work 

 done. The fourth man, E.F.S., gave off considerably more heat 

 during the working period and also accomplished more work; and 

 then we come to the astounding results of the experiment with 

 Mr. Butler in which he gave off 619 calories and accomplished the 

 enormous amount of 112 calories of muscular work. The remain- 

 ing experiments with Mr. Butler were made with the idea of de- 

 creasing the muscular work and noting the effect on the heat pro- 

 duction. You can see in a general way that when the total heat 

 falls off, the work done falls off". 



Perhaps of greatest interest is the comparison of these different 

 men with regard to their efficiency. There are a number of methods 

 whereby the efficiency can be computed from the figures given in 

 the table. Theoretically we can say that in the first instance for 

 every 49 calories of heat produced, there were required 339 calories 



