110 
MUSCULAR WORK 
Table 108. — Results of experiments with N. B., as reported by Benedict and Carpenter. 
[Amounts per hour]. 
(a) 
M 
(c) 
W) 
(e) 
if) 
(ff) 
Date. 
Period. 
Carbon 
Oxygen 
Heat 
Heat equiv- 
Heat above 
Net 
Current. 
dioxide 
ab- 
pro- 
alent of 
resting 
metabolism. 
efficiency. 
eliminated. 
sorbed. 
duced. 
work done. 
(eXlOO)-i-f 
1904. 
amp. 
grams. 
grams. 
cals. 
cals. 
cals. 
p. ct. 
Oct. 21 
First 
1.25 
215.2 
625.4 
104.5 
531.2 
19.7 
22 
First 
Rest. 
28.6 
94.2 
22 
Second. . . 
1.25 
208.1 
616.2 
115.7 
522.0 
22.2 
24 
First 
No load. 
62.2 
182.5 
1905. 
Jan. 23 
First 
Rest. 
29.4 
22.8 
89.7 
23 
Second. . . 
1.25 
231.0 
183.4 
608.0 
113.8 
518.3 
22.0 
23 
Third.... 
1.25 
210.4 
174.0 
625.8 
114.7 
536.2 
21.4 
24 
First 
.90 
153.5 
142.8 
473.3 
79.8 
383.7 
20.8 
24 
Second . . . 
.90 
159.6 
140.2 
468.2 
77.7 
378.6 
20.5 
25 
First 
.80 
124.8 
114.6 
392.1 
64.1 
302.5 
21.2 
25 
Second . . . 
.80 
139.8 
125.7 
409.6 
66.6 
320.0 
20.8 
26 
First 
No load. 
63.5 
57.4 
181.6 
26 
Second. . . 
0.70 
138.2 
111.1 
382.4 
59.9 
292.7 
20.5 
A summary of the results obtained with all of the work experiments with 
these subjects is given in table 109, which shows the gross and net efficiency 
for each man. 
Table 109. — Average mechanical efficiency of subjects in work experiments made by 
Benedict and Carpenter. 
[Amounts per hour.] 
Subject. 
J. C. W., average of 6 days 
B. F. D., average of 3 experiments 
A. L. L., average of 6 days 
A. L. L., extra severe work 1 day. 
E. F. S., one day 
N. B., average of 4 experiments. . 
N. B., average of 2 experiments . . 
Do 
N. B., one experiment 
Heat 
equiva- 
lent of 
muscular 
work. 
cals. 
49 
45 
38 
46 
51 
112 
79 
65 
60 
Mechanical 
efficiency. 
Gross. Net. 
p. ct. 
14.5 
14.2 
12.7 
14.1 
12.8 
18.1 
16.8 
16.2 
15.7 
p. ct. 
21.6 
21.2 
19.7 
20.8 
18.1 
21.3 
20.8 
21.0 
20.7 
The authors also computed the mechanical efficiency based on the coasting 
or "no-load" values of these men; the results are abstracted in table 110. 
These values are wrong, owing to an erroneous assumption for the friction 
of the ergometer." Finally, the effect on the efficiency of increasing the ex- 
Table 110. — Mechanical efficiency based on coasting as reported by Benedict and Carpenter. 
[Amounts per hour.] 
Subject. 
(a) 
Current. 
(b) 
Revolu- 
tions 
per 
minute. 
(c) 
Heat pro- 
duced dur- 
ing work. 
Heat pro- 
duced dur- 
ing coasting. 
(e) 
Estimated 
heat re- 
quired for 
work. 
(.c—d) 
(/) 
Heat equi- 
valent of 
work (less 
friction). 1 
(s) 
Net 
efficiency. 
(/X 100) -he 
N. B. 
N. B. 
N. B. 
N. B. 
A. L. L. 
amp. 
1.25 
.90 
.80 
.70 
1.25 
83 
76 
70 
78 
cals. 
617 
471 
401 
382 
299 
cals. 
182 
167 
153 
171 
135 
en Is. 
435 
304 
248 
211 
164 
cals. 
107 
72 
58 
52 
35.5 
p. ct. 
24.6 
23.7 
23.4 
24.6 
21.6 
1 Later researches with the apparatus show that the values in this column are erroneous. 
Cady, Carnegie Institution of Washington Publication No. 167, 1912, p. 22.) 
(See Benedict and 
8 For discussion of this point see p. 143 of this report. 
