PBEPARATI02S- OF BEES FOE OUTJDOOE WIKTERIITG. 7 



rials, provided, of course, that obviously poor tilings such, as corn 

 fodder and straw be eliminated. Sawdust, fine planer shavings, 

 forest leaves, chaff 5 broken cork^ and such materials may be used, the 

 choice depending chiefly on the availability of the materials. In 

 general it may be stated that the smaller and the more numerous the 

 dead air spaces confined in the packing, the greater will be its effi- 

 ciency in insulation. If forest leaves are used they must be gathered 

 the year before and stored, as the leaves fall some time after the 

 bees should be packed. If sawdust is used it is best not to pack it 

 down tight, but if forest leaves or planer shavings are employed it is 

 essential that they be packed in closely and that the containers be 

 completely filled. Broken cork, such as is used in the shipping of 

 certain types of grapes, is good and has the advantage that it does not 

 hold moisture as does sawdust. In all cases the packing should be 

 placed in some sort of box which will be rain-proof and thus protect 

 the insulation from rains and snow, for all insulating materials lose 

 part of their efficiency when wet. 



BOTTOM PACKING. 



There has been considerable discussion among beekeepers as to the 

 value of placing packing material below the bottom boards of the hives. 

 This is usually provided by placing the hives on 2 by 4 inch supports 

 or on racks of 4-inch material. Those who have opposed this have 

 pointed out that " heat rises," overlooking the fact that while warm 

 air attempts to rise, if this is impossible other avenues of escape of 

 warm-air currents may be set up. Furthermore, and more im- 

 portant, they have overlooked the important fact that heat escapes 

 from the hive not only by convection currents but by conduction and 

 radiation as well. In an extensive series of experiments performed 

 by the writers it was found that in hives packed at the top and 

 sides most of the heat escapes through the bottom boards: in fact, 

 this was so noticeable that the packing at the top and sides never 

 served its full purpose so long as heat was escaping rapidly at the 

 bottoms. It may be stated, therefore, that so long as the botton^s 

 are unprotected there is little insulating value in materials piled on 

 the top and sides beyond about 2 inches. This amount is insufficient 

 for most parts of the United States, therefore bottom packing should 

 be considered as absolutely essential wherever bees are packed. 



To get the value of bottom packing it is absolutely essential that 

 the entrance be reduced, but it need not be closed. In a long series 

 of temperature readings on hives packed for several winters, the 

 authors were able to keep a temperature of 50° F. on the bottom 

 boards of packed hives directly behind the enti^ance openings. Those 

 who have condemned bottom packing have labored, under the mis- 

 taken notion that it is impossible to prevent currents of cold air 



