142 
MUSCULAR WORK 
Table 126. — Continued. 
[Basal values obtained with subject lying on couch.] 
Date. 
Revolu- 
tions per 
minute. 
Heat equiv- 
alent of 
external 
work per 
minute. 
Net 
efficiency. 
Apr. 8 
Av. 3 periods . 
Feb. 26 
Feb. 29 
Feb. 23 
Av. 4 periods . 
1912. 
Apr. 9 
Av. 3 periods . 
Feb. 27 
Av. 2 periods . 
Feb. 27 
Feb. 26 
Feb. 23 
Feb. 26 
Av. 4 periods 
Effective work, 1.35 calories. 
70 
71 
71 
1.33 
1.35 
1.36 
23.0 
23.3 
23.0 
71 
1.34 
23.1 
94 
1.29 
20.4 
102 
104 
107 
108 
1.35 
1.35 
1.35 
1.37 
18.1 
17.0 
15.8 
17.2 
105 
1.35 
17.0 
Effective work, 1.20-1.25 calories. 
71 
71 
72 
1.20 
1.19 
1.20 
21.9 
21.4 
21.3 
72 
1.20 
21.5 
82 
83 
1.18 
1.20 
20.7 
20.0 
83 
1.19 
20.4 
86 
87 
88 
93 
1.22 
1.24 
1.24 
1.28 
20.6 
19.6 
18.0 
19.8 
88 
1.26 
19.5 
of approximately 1.20 to 1.25 calories, the average net efficiency with 72 
revolutions was 21.5 per cent; with 83 revolutions, 20.4 per cent; and with 
88 revolutions, 19.5 per cent. 
From a consideration of these various methods of computing the energy 
efficiency of the body, it is obvious that there are grave difficulties in the way 
of securing a base-line which will embrace only the extraneous muscular 
motions incidental to riding with load upon which could be superimposed a 
definite amount of muscular exertion productive of external muscular work. 
Certain it is that the various base-lines we have considered — lying, sitting, 
and riding no load with and without the motor — fail to meet this requirement. 
The comparisons previously made of the experiments with currents of 0.5 
ampere and 1.5 amperes, and of 0.95 ampere and 1.5 amperes, indicate that 
experiments used for a base-line should be accompanied by an even greater 
amount of muscular work than would be required to overcome ordinary 
friction. With the best conditions it is possible to have the work done to 
such advantage that the increase in the effective muscular work may be as 
high as 33 per cent of the increase in the total heat output. On the other 
hand, we have to consider in this connection the various influences of speed 
upon the efficiency, since it has been clearly brought out in the previous dis- 
cussion that the greater the speed the less is the efficiency, the greatest 
efficiency with the subject M. A. M. being obtained when he rode at the rate 
of 70 to 80 revolutions per minute. The ideal comparison, therefore, is found 
