144 
MUSCULAR WORK 
external work. According to the results reported by Benedict and Carpenter, 
the increase in load does not materially affect the efficiency of the body as 
a machine, all of the values with but one exception being approximately 
21 per cent. The authors call attention to what may now be recognized 
as a very important fact that the speeds per minute were not uniform with 
all degrees of magnetization of the field and that the experiments were not 
made under ideal conditions for studying this particular point. Neverthe- 
less the discrepancy between the 21 per cent found by them and the 27 per 
cent found by us (see table 122) is altogether too wide to be accounted for 
by any errors due to variations in speed. In order to show this more clearly, 
our results, computed on the basis of calories per hour, have been brought 
together in table 128 without regard to variations in speed. While these 
values confirm the inference drawn from their results by Benedict and Car- 
penter that increase in load does not materially affect the efficiency of the 
body, there is shown in general a slight tendency for the work to be done more 
efficiently in changing from a moderately heavy load to one still heavier than 
when changing from a light to a heavy load, that is, the percentage of effi- 
Table 128. — Effect of increased load on body efficiency without regard to variations in speed. 1 
[Amounts pier hour.] 
(a) 
(6) 
(c) 
(d) 
(a) 
(b) 
(c) 
(d) 
Increase 
Increase 
Increase 
Effi- 
Increase 
Increase 
Increase 
Effi- 
Subject. 
in mag- 
of total 
of heat of 
ciency. 
Subject. 
in mag- 
of total 
of heat of 
ciency. 
netization 
from — 
heat. 
external 
work. 
cXIOO 
b 
netization 
from — 
heat. 
external 
work. 
cXIOO 
b 
amp. 
cals. 
cals. 
p. ct. 
amp. 
cals. 
cals. 
p. ct. 
M.A. M... 
0.5 to 0.95 
144 
49 
34.0 
M.A. M... 
0.5 to 1.5 
289 
89 
30.8 
140 
44 
31.4 
308 
91 
29.5 
148 
44 
29.7 
323 
96 
29.7 
196 
48 
24.5 
322 
97 
30.1 
185 
48 
25.9 
346 
94 
27.2 
191 
48 
25.1 
220 
67 
30.5 
M.A. M... 
0.5 to 1.1 
158 
43 
27.2 
211 
65 
30.8 
163 
43 
26.4 
217 
65 
30.0 
168 
43 
25.6 
193 
64 
33.2 
275 
62 
22.5 
219 
65 
29.7 
M. A. M... 
0.5 to 1.25 
185 
52 
28.1 
206 
64 
31.1 
176 
52 
29.5 
218 
66 
30.3 
184 
53 
28.8 
215 
66 
30.7 
331 
77 
23.3 
221 
66 
29.9 
J. J. C 
0.5 to 1.5 
235 
67 
28.5 
215 
65 
30.2 
249 
67 
26.9 
340 
94 
27.6 
K. H. A.... 
0.5 to 1.5 
290 
73 
25.2 
343 
94 
27.4 
269 
74 
27.5 
0.95 to 1.5 
84 
40 
47.6 
286 
73 
25.5 
113 
41 
36.3 
316 
73 
23.1 
131 
40 
30.5 
J. E. F 
0.5 to 1.5 
226 
65 
28.8 
123 
41 
33.3 
269 
75 
27.9 
127 
40 
31.5 
245 
64 
26.1 
130 
41 
31.5 
270 
65 
24.1 
116 
49 
42.2 
E. P. C 
0.5 to 1.5 
210 
60 
28.6 
145 
46 
31.7 
192 
59 
30.7 
139 
46 
33.1 
M. A. M... 
0.5 to 1.5 
365 
98 
26.8 
» Values taken from columns e and / of tables 12] , 122, and 123, and calculated to the per hour basis. 
ciency in changing from 0.95 to 1.5 amperes was slightly higher than in 
changing from 0.5 to 0.95 ampere. 6 The greatest discrepancy, however, is 
the fact that the percentages found by Benedict and Carpenter average about 
21 per cent while ours average much nearer 28 to 30 per cent. Although the 
o Benedict and Carpenter, loc. cit., p. 42. , 
6 This increase in efficiency with increasing load is of special interest as the result is quite opposite to that ot 
earlier workers and, indeed, not in accord with experience with prime motors. As an evidence of tne 
flexibility of the human body, this observation is worthy of further study. 
