8 BULLETIN 988, TJ. S. DEPT. OF AGRICULTURE. 
RESULTS OBTAINED IN THE EXPERIMENT. 
Data indicating the physiological activity of the bees are sum- 
marized in the following table with others showing the experimental 
conditions. 
Summary of experimental data. 
Date. 
Temper- 
ature of 
air in the 
chamber. 
Humid- 
ity of 
air in 
chamber. 
C0 2 in 
air in 
chamber. 
Oxygen 
in air in 
chamber. 
Water 
vapor 
taken 
from the 
air. 
Carbon 
dioxid 
produced. 
Oxygen 
con- 
sumed. 
Heat 
gener- 
ated. 
Dec. 13 
° a 
7.3 to 8.8 
6.4 to 8.0 
6.1 to 8.2 
6.3 to 7.0 
6.3 to 7.6 
7.8 to 9.2 
7.1 to 7.8 
6.9 to 7.9 
6.8 to 8.3 
7.4 to 7.7 
7.6 to 8.8 
Per cent. 
Per cent. 
0.53 
1.42 
.87 
.81 
1.08 
.52 
.63 
.23 
1.40 
.51 
.29 
Per cent. 
15.2 
16.8 
17.1 
21.1 
22.6 
24.5 
26.4 
28.9 
24.5 
18.2 
7.3 
Grams. 
17.1 
3.4 
5.0 
8.1 
8.3 
6.9 
26.5 
25.9 
22.2 
23.2 
15.9 
Liters. 
9.6 
10.4 
11.7 
13.3 
12.8 
12.1 
12.9 
14.5 
11.0 
16.3 
14.9 
Liters. 
Calories. 
Dec. 14 
75 to 90 
77 to 90 
77 to 95 
72 to 93 
76 to 95 
50 to 86 
49 to 66 
47 to 66 
45 to 65 
50 to 55 
Dec. 15 
Dec. 16 
Dee.17 . 
Dec. 18 
Dec. 19 
Dec. 20 
Dec. 21 
Dec. 22 
Dec. 23 
Total, omitting! 
irst dav . . 
129.9 
138.4 
683 
With the warm conditions prevailing in the laboratory, the cool- 
ing capacity of the apparatus, which had been constructed for work 
at higher temperatures, was not sufficient to chill the hive as much 
as had been desired when this experiment was planned, consequently 
the bees were not subjected to very low temperatures. Those shown 
in the table were measured with an electrical resistance thermometer 
suspended in the air above the hive, which was as warm as that in 
any part of the apparatus, but the readings on two thermometers 
in other parts of the chamber did not differ materially from these. 
The figures shown are the lowest and highest temperatures observed 
each day, but there was no uniformity in the time at which these 
occurred. The fluctuations in temperature are shown in the curve 
for thermocouple No. 15 on pages 15 to 18. The maximum range, 
from 6.1° to 9.2° C, was in the vicinity of the temperature which 
beekeepers usually consider favorable for bees wintering in cellars. 
The daily production of carbon dioxid shown in the table is an 
index of the amount of work performed by the bees. This quantity 
was derived, in the manner previously explained, from the weight 
of the carbon-dioxid absorber, which was taken every 24 hours. Any 
error in these figures, with the possible exception of those for Decem- 
ber 21 and 22, which are explained later, is believed to be of small 
magnitude. The most significant error that could occur would be 
due to the fact that the circulation of air was not directly through 
the hive, but through the chamber in which the hive was inclosed. 
In some cases there might be an accumulation of carbon dioxid in 
the hive in one period which would escape in a later period, with a 
