ILLINOIS STATE BEE-KEEPERS' ASSOCIATION 



79 



ployed by the bee-keepers who winter 

 their bees most successfully would 

 probably show that the quotation given 

 above from Hutchinson is correct. 



- Effect on the Humidity of Changing 

 the Outside Temperatures. Any change 

 in the temperature of the bee cellar 

 may affect the humidity of the air in 

 the hive in two ways. As the optimum 

 cellar temperature is approached, the 

 heat produced by a normal colony will 

 diminish and this decreases the food 

 consumed and consequently the water 

 produced. The widely varying reports 

 of the food consumed by bees in cellars 

 find their explanation chiefly in the 

 difference in the temp.erature of the 

 cluster. As the cellar is cooled below 

 the optimum not only is there more 

 water produced but the cooler atmos- 

 phere is incapable of holding so much 

 and there is therefore an augumented 

 cause for condensation. 



In this connection it may be of in- 

 terest to record a few observations 

 made by one of the authors on bee 

 cellars not long since. The first cellar 

 was away from any house, was venti- 

 lated by the sub-earth system and was 

 without any artificial heat. The tem- 

 perature of the air at the floor was 

 40°F. and in the center of the cellar, 

 4] op There was little circulation of 

 air, and moisture had condensed free- 

 ly in the chamber above the cellar 

 proper, under the roof. In this cellar 

 were 98 colonies in 24 stacks. Of 

 these, condensed moisture was seen on 

 the bottom boards of 21 in the bottom 

 tier, 11 in the next tier, 3 in the third 

 and 6 in the top tier. There was no 

 condensed moisture on the floor. The 

 only adequate explanation for the 

 greater number of wet colonies in the 

 lower tiers is the slightly lower tem- 

 perature at the floor. If, now, there 

 had been more ventilation provided 

 without greatly lowering the cellar 

 temperature, this moisture might at 

 least have reached the chamber above 

 the cellar before condensing and 

 doubtless if the temperature could have 

 been riaised a couple of degrees all of 

 the condensed moisture would have 

 disappeared from the bottom boards. 

 There might still have been condensa- 

 tion on the covers, where it first ap- 

 pears, but this too would doubtless 

 have evaporated at 45°F. with good 

 ventilation. 



In a second cellar where the tempera- 



ture was 45.5°F. at the floor and SQOF. 

 six and one -half feet from the floor, 

 there was no condensed moisture in 

 any of the 93 colonies. Here the ventil- 

 ation was much more abundant and 

 the cellar was artificially heated. In a 

 third cellar, temperature 40 °F. five feet 

 from the floor, there was moisture on 

 several covers but none on the bottom 

 boards. The ventilation was excellent. 

 In a fourth cellar temperature 52. 5°F., 

 no condensation was observed even on 

 the covers. It therefore appears from 

 these few observations that in the two 

 cellars at 40 °F. the moisture was more 

 in evidence in the poorly ventilated 

 cellar and that when the temperature 

 was raised to 45.5 or 52.5°F. no conden- 

 sation occurred. In this connection it 

 should be remembered that the cellar 

 temperature is often higher than that 

 of the outer air, thus giving the atmos- 

 phere a greater capacity for water 

 vapor. For example, if air comes from 

 the outside at 0.0 °F. into a cellar where 

 it is warmed to 45 °F. its capacity for 

 moisture is increased thereby almost 

 eight times (barometer 30 in.) so that 

 even if the atmosphere at 0°F. ia sat- 

 urated it is capable of taking up much 

 more moisture when it reaches the cel- 

 lar temperature. Moist air passing 

 from the cellar will often cause frost 

 to form about the ventilating holes. 



The only conclusions that can safely 

 be made from the data on these four 

 cellars is that concerning the capacity 

 of the atmosphere for water at different 

 temperatures. Other factors entered 

 into the wintering of bees in these 

 four cellars so that probably no re- 

 liable conclusions could be formed from 

 data as to the food consumed by the 

 various colonies, even if these were 

 available. 



In discussing the condensation of 

 moisture in the hive and the various 

 methods by vv^hich it may be avoided, 

 one must not lose sight of the fact 

 that little is definitely known as to the 

 effects of such condensation or of a 

 high relative humidity on the winter- 

 ing of bees. From the experience of 

 numerous bee-keepers there is justifi- 

 cation for concluding that bees winter 

 better in the dryer cellars but it is 

 not so clear whether this statement 

 would hold true for all cellar tempera- 

 tures. In most systems of cellar ven- 

 tilation the object accomplished is not 

 So much to provide oxygen for the bees 

 as to eliminate the exhaled moisture 



