143 
given off in the several periods, are 28.1, 27. 7^ 26.3, and 17.9, 
respectively. 
The average hourly rate for the 20 days of the 6 work experi- 
ments with E. O. and J. F. S. was 152.8 calories. The rates for the 
different periods, beginning with 7 a. m.. were 212. 222.5. 106.5, 
and 68.2 calories, respectively. The corresponding percentages are 
34.8, 36.5, 17.5. and 11.2. 
It thus appears that in the two day periods in which the subjects 
were engaged in active muscular exercise for 8 hours the quantity of 
heat given off was more than twice as much as in the corresponding 
periods of the rest experiments. In the first night period the amount 
per hour in the work experiments was not greatly in excess of that in 
the rest experiments (106.5 as compared with 98.5 calories). In the 
second night period the quantities were nearly the same (68.2 in the 
work experiments and 67.3 calories in the rest experiments). 
The uniformity in the amounts of heat given off during the second 
night period calls for special notice. In the rest experiments with 
E. O.. covering 33 days, the range is from 62.8 to 77.8 and the aver- 
age 69.2 calories per hour. In the experiment with A. W. S.. covering 
3 days, the range per hour is from 62.7 to 70.1 and the average 67.5 
calories. In the 12 days of the work experiments with E. O. the 
amounts are a little larger than in the rest experiments with the same 
subject, ranging from 68. 8 to 79.6 and averaging 74 calories per hour. 
That the elimination of heat during this period is larger in the work 
than in the rest experiments is perhaps explained by the fact that 
while the subject was decidedly tired at night, and supposed that 
he slept more soundly than in the rest experiments, he moved more, 
and to the observers outside the chamber he appeared more rest- 
less. In the work experiments with J. F. S. also the amounts dur- 
ing this period are slightly larger than in the rest experiments, rang- 
ing from 60.1 to 70 and averaging 64.2 calories per hour. It is 
noticeable that the rate in the second night period is smaller with 
J. F. S: than with E. O.. the ratio of the former to the latter being 
about the same in both work and rest experiments 
From the results obtained in the second night periods in these exper- 
iments it would seem that from 65 to 70 calories per hour might be 
not far from representing an average elimination of heat by a healthy, 
active man in the time of minimum bodily activity. 
Relation between dif/iination of heat ami of carbon dioxid. — The 
rates of elimination of heat and of carbon dioxid in the different periods 
are nearly parallel, as will be seen by comparing the figures of Tables 
147 and 150. Both these values in the two day periods of the work 
experiments are largely in excess of the similar values in the same 
periods of the rest experiments. The values for both thesr factors in 
the second night periods of the same experiments, which was one of 
quiet sleep, were small and noticeably uniform. 
