ILLINOIS STATE BEE-KEEPERS' ASSOCIATION 



73 



mometers in the cluster (1, 2, and. 5) 

 gave temperature readings quite close 

 together, while thermometer 6, which 

 was near the cluster, gave readings 

 intermediate between the three ther- 

 mometers of the cluster and the four 

 others in the hive, farther from the 

 cluster. After November 22 the records 

 of the thermometers in the cluster 

 were more widely separated and the 

 temperature of the center of the cluster 

 (shown on thermometer 5) tended to 

 rise gradually. It varied constantly, 

 but by December 7, and from then until 

 the end of the month, it averaged be- 

 tween 69° and 75 °F. On November 

 29 and December 12 the cluster tem- 

 perature rose to over 88 op. From the 

 1st of January until March 6, which 

 ended the regular series of readings, the 

 cluster temperature became more and 

 more irregular, and on January 20 the 

 cluster moved (probablj' to accommodate 

 itself to the stores) until thermometer 

 2 was nearer the center and showed 

 a higher temperature than thermometer 

 5. The size of the cluster was gradu- 

 ally decreased by the death of bees, 

 and all the thermometers except 2 and 

 6 show a gradual decrease in temper- 

 ature until finally, from about Feb- 

 ruary 25 to March 6, they are all low 

 and of nearly equal temperature. The 

 two thermometers giving high readings 

 continued to show in general a higher 

 and higher average temperature and 

 to become more irregular (except from 

 February 15 to March 1), the periods 

 of increased heat becoming more fre- 

 quent. There was absolutely no regu- 

 larity in these intervals. After Feb- 

 ruary 1 the temperature of the cluster 

 varied between 75° and 91°F., the 

 average from February 1 being 85.4 °F. 

 On March 6 all colonies in the con- 

 stant-temperature room except two 

 were removed. The colony described 

 above (No. 1) and one other (No. 2), 

 not to be described at present, were 

 left. On Mai'ch 7 at 9 a. m. the tem- 

 perature of the room stood at 42 °F., 

 and the temperature of the interior of 

 the cluster was about 84°F. The brine 

 which cooled the room was then shut 

 oft' and the temperature of the room 

 rose very slowly and regularly, until 

 on March 11 at 8.45 a. m. it was 64°F. 

 For the first day the temperature of 

 the cluster was slightly variable, and 

 at 10.45 p. m. thermometer 6, which 

 had been cooler than thermometer 2, 

 showed a rise in temperature (prob- 



ably due to a shifting of the cluster), 

 and from then on to the 24th they were 

 nearly of the same temperature at all 

 times. On March 8, at 3 a. m., ther- 

 mometer 2 rose to 87° F. (room tem- 

 perature, 48.5 °F.), having previously 

 shown a cooling. The cluster temper- 

 ature then dropped slightly, showing 

 relatively little variation until at 4.15 

 p. m., March 9, it stood at 77.3°F. 

 (room temperature, 55.7°F.). As the 

 room temperature continued to rise, 

 the cluster temperature increased still 

 more rapidly, until at 8.15 a. m., March 

 11, it reached 93°F. (room temperature, 

 64.2°F.). A little brine was now turned 

 on, sufficient to lower the temperature 

 gradually to 58°F. at 9 a. m., March 12, 

 and it again rose to 63.3°F. at 5.45 p. 

 m., March 15. During this period the 

 cluster temperature followed the room 

 temperature, but remained constantly 

 over 20° warmer. The room was again 

 cooled slowly, and the cluster temper- 

 ature dropped until on March 16, at 3 

 p. m., the room was 49 °F. and the 

 cluster 77.5°F. As the room continued 

 ^0 cool, the cluster temperature in- 

 creased, the bees responding to the 

 colder temperature, until at 4.15 a. m., 

 March 17, the room was 48 °F. and the 

 cluster 88°F. The room then gradual- 

 ly warmed, and again the temperature 

 of the cluster dropped and then again 

 rose with the room temperature, re- 

 maining always over 20° warmer. At 

 6.45 p. m., March 19, the brine was 

 turned on full and the room cooled 

 rapidly, reaching the minimum of 13°F. 

 at 9 p. m., March 20. At no time, how- 

 ever, did any of the thermometers in 

 the hive record a temperature below 

 33 °F. Here it remained constant 

 within 0.1°F. for about six hours, dur- 

 ing which time the cluster tempera- 

 ture varied between 86.5° and 89.5°F. 

 (a difference between the room and the 

 cluster temperatures of 73° to 76°F.). 

 The brine was now shut off and the 

 room again warmed until 9 a. m., 

 March 24, when it reached a tempera- 

 ture of 44.5°F. During this warming 

 the cluster cooled until at the close it 

 was varying between 72° and 79 °F. 



As stated above, the colony was now 

 (9 a. m., March 24) removed for a 

 flight and put back the same day at 

 7 p. m. In the meantime the room was 

 cooled to 33°F. When the bees were 

 put back into the room the tempera- 

 ture of the entire inside of the hive 

 showed great variation and naturally 



