8 BULLETIN 988, U. 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 



° C. 



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 







Dec. 17 







Dec. 18 







Dec. 19 







Dec. 20 







Dec. 21 







Dec. 22 







Dec. 23 













Total, omitting i 



irst day . . 











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 



