GLEANINGS IN BEE CULTURE 



October, 1918 



less active (begin hibernation), the honey- 

 bee becomes more active and generates heat, 

 in some cases until the temperature within 

 the cluster is as high as that of the brood- 

 nest in summer. To sum up, when the tem- 

 perature of a colony of undisturbed brood- 

 less bees is above 57° F. and below about 

 69° F., the bees are quiet and their tem- 

 perature drifts with the outer temperature; 

 at lower temperatures they form a compact 

 cluster, and the temperature within it is 

 raised by heat generated by the bees. ' ' 



This is. certainly a strong argument in fa- 

 vor of better protection against the cold of 

 winter than most of us have been giving 

 our bees. When we realize that they main- 

 tain a temperature never lower than 57° F. 

 and are quiet and satisfied at temperatures 

 between 57° F. and 69° F. (temperatures 

 almost as high as that which we need in our 

 living rooms), we can understand the need 

 for a better housing of the bees during 

 cold weather. When we remember the bit- 

 ter cold and high winds of last winter, and 

 how it was necessary to burn tons and tons 

 of coal to keep our homes even above 60° F., 

 we wonder that the bees were able to sur- 

 vive, when wintered out of doors, with mus- 

 cular activity the only means of heating 

 their homes. The month of October is pre- 

 eminently the month for packing the bees 

 that are to be wintered out of doors. 

 How Heat Escapes from the Hive. 



The heat that is generated by the bees can 

 escape from within the hive by two avenues 

 only. (1) It may pass thru the walls of 

 the hive by the comparatively slow process 

 of being transmitted from particle to particle 

 of the material forming the walls until it 

 reaches the outer surface where it is either 

 transmitted to the air and carried away or 

 lost from the outer surface by radiation. 



(2) It may be carried out of the hive by 

 air currents thru the entrance or other open- 

 ings. The air currents may be caused by the 

 wind blowing into the entrance, sweeping 

 around and over the cluster, then out some 

 other opening or another part of the en- 

 trance; or they may be weaker currents, set 

 up within the hive because of differences of 

 temperature there. Winter cases and pack- 

 ing prevent heat escape in the one case; con- 

 tracted entrances, in the other. 



Conditions Influencing Loss of Heat 

 Thru the Walls. 

 Physicists tell us that the rate at which 

 heat flows thru a solid depends upon four 

 things only, which when put into terms of a 

 double-walled beehive are: (1) material 

 used for packing, (2) thickness of packing, 



(3) area of walls, ceiling and floor of the 

 inner chamber, (4) the difference in tem- 

 perature between the inner and outer sur- 

 faces. It follows, therefore, that we can 

 decrease the loss of heat thru the walls by 

 using better material for packing, by in- 

 creasing the thickness of the packing, by de- 

 creasing the size of tlie inner chamber, and 

 by locating the apiary in a sheltered place 

 to keep the wind from cooling the outer 



surface of the winter cases rapidly, and, at 

 the same time, where the sun can shine on 

 them to reduce or stop the outward flow of 

 heat while the sun is shining. 

 Packing Material. 



The material for packing should not be 

 too coarse, such as straw, coarse planer 

 shavings or forest leaves thrown in loosely, 

 because such material permits currents of 

 warmer air to rise and escape from the 

 packing, thus carrying the heat away more 

 rapidly. Also high winds may force air 

 currents thru cracks in the outer case into 

 and entirely thru such coarse material, 

 rapidly carrying away the heat. Such ma- 

 terial as wheat chaff, sawdust, fine planer 

 shavings, or crushed and finely broken for- 

 est leaves, are perhaps about equally good 

 for retarding the flow of heat. Sawdust will 

 absorb and transmit moisture, if the winter 

 case leaks. 



Effect of Size of Winter Chamber. 



Years ago when chaff hives and chaff di- 

 vision-boards were more commonly used, 

 many beekeepers reduced the winter cham- 

 ber to fit the cluster, filling the remaining 

 space with these close-fitting chaff-packed 

 division-boards. P!resent-day management 

 is apparently going in the opposite direction, 

 some beekeepers even using two hive-bodies 

 for the winter chamber. The danger' here 

 is that some may increase the size of the 

 winter chamber without at the same time 

 increasing the thickness of the packing. 

 Since every square inch on the inner surface 

 may be considered as an avenue for the es- 

 cape of a certain amount of heat, it follows 

 that, if we double this surface without 

 changing other conditions, we double the 

 rate of the loss of heat thru the walls. To 

 secure the same degree of protection when 

 the surface of the inner chamber is doubled, 

 it is necessary to double the amount of 

 packing. 



The Entrance. 



The movement of air currents thru the 

 entrance is influenced by its size and shape 

 and the presence or absence of other open- 

 ings in the hive. If there is but a single small 

 opening, there is little opportunity for the 

 wind to blow thru it into the hive, since air 

 cannot enter unless air from the inside can 

 escape at the same time. When the usual 

 long, narrow entrance is used, wind may 

 blow into the hive at one side of the en- 

 trance and force the warm air out at the 

 other. A single small entrance, together with 

 sealed covers, should prevent almost entire- 

 ly the conveyance of heat thru the entrance 

 by air currents. 



The ideal condition toward which to 

 strive is a winter chamber which fits the 

 size of the cluster, or rather a cluster big 

 enough to fill the winter chamber, so that 

 the cluster touches and warms its walls, and 

 these walls so well protected that it is not 

 necessary for the bees to draw away from 

 them in severe weather to form another 

 wall of living bees as an insulating crust for 

 the cluster. 



