416 THE BEEKEEPERS' REVIEW 



single-walled hives. 



Types of insulation — Various materials are used for insulation. Besides 

 those named above, paper, dry leaves, and many other substances are in use. 

 Most of the common insulating materials depend on small confined dead-air 

 spaces for their insulating value, and, in general, the more finely divided the 

 air spaces the more efficient the material. Sawdust is usually condemned, be- 

 cause if moisture escapes from the hive into the packing it is retained and the 

 insulating value is reduced. However, if a colony is sufficiently packed, mois- 

 ture does not condense, except possibly at extremely low external tempera- 

 tures, and this objection to sawdust is removed. From observations so far 

 made it appears that the beekeeper may use the materials most easily obtained. 

 If dry leaves are used, they should be packed tight, but sawdust should simply 

 be poured in place without being packed tight. 



The entrance — The weak place in hive insulation is the entrance. An open- 

 ing 8 inches wide and % inch high is abundant, it usually being constructed 

 as a tunnel through the packing. In cold weather this might be still further 

 reduced. The opening should be shielded from the wind, to prevent a rapid loss 

 of heat, for if the wind blows against the entrance the heat stored up in the 

 packing is lost both to the outside and the inside. The only reason for an en- 

 trance as large as the size mentioned above is the danger that dead bees will 

 drop from the combs and block a smaller entrance. Since the number of dead 

 bees is greatly reduced in well-insulated hives this is less important, and 

 furthermore, if the air within the hive is warmed to 57 degrees F. the dead 

 bees will be pushed outside, even in freezing weather. 



Methods of packing — The exact method of packing is not especially im- 

 portant, provided enough insulation is given on all sides. Colonies may be 

 packed singly in any sort of box, or they may be packed in groups of four, as 

 previously described (p. 414). Some beekeepers arrange colonies in long rows 

 and apply insulation to the whole row. The placing of several hives in con- 

 tact has the advantage that the colonies insulate one another. If arranged 

 in groups of four, two facing east and two west, they may be left on the same 

 stand throughout the year and are readily manipulated during summer. If 

 in long rows close together, summer manipulations are impeded, unless the hives 

 are moved after the insulation is removed. Placing colonies in long rows is 

 therefore not advisable. Whatever type of outer case is used, it should be 

 tight, to prevent rain and snow from wetting the insulating material. 



A rather common practice is to pack the hive at the sides, top, and rear, 

 but to leave the front unprotected and faced to the south, the object being to 

 utilize the heat of the sun to warm up the interior of the hive and reduce the 

 work of the bees. Any place through which external heat may readily reach 

 the interior of the hive is also efficient as an avenue through which heat may 

 be lost when the sun is not shining. Since the sun shines less than half the time 

 in winter, making no allowance for cloudy days, the weakness of the argument 

 for this practice is obvious. A similar practice is to paint the packing cases a 

 dark color to absorb the sun's heat. Considerably more detailed work is needed to 

 determine to what extent this source of heat is of value to the colony. 



Time for packing — At the time of the first killing frost the beekeeper 

 should promptly remove supers, if any are on his hives. If the bees are not 

 adequately supplied with good stores for winter these should now be given 

 immediately, and, when the feeding is finished, the winter insulation should 

 be applied at once. At this time bees are the quietest of any period of the 



