THE BEEKEEPERS' REVIEW 415 



were in much better condition than colonies left unpi'otected, and cases of this 

 general type are being constructed for the entire apiary at Drummond, except 

 for such colonies as are used in other wintering experiments. The dimensions 

 here stated should by no means be accepted as best for other localities, espec- 

 ially those farther north, where the protection should be heavier, but in this 

 particular packing case the temperature of the air within the hive but outside 

 the cluster usually stood at about 55 degrees to 57 degrees F., except for a 

 reduction in temperature under one condition to be discussed on the next page. 

 The aim of the beekeeper should be to keep the air about the bees at about 57 

 degrees F., at which temperature there is no condensation of moisture within 

 the hive, even on the inside of the cover, where it first appears. It might be 

 inferred that if double the amount of packing had been used the temperature 

 of the air about the bees would have been too high. This is not the case, for 

 bees cease heat-generation when the temperature reaches 57 degres F., (or 

 even sooner when the surrounding temperature is risingi), and the tempera- 

 ture will not exceed 57 degrees F. unless that of the outer air remains higher 

 than that for a considerable period. 



Bees well protected and with good stores do not fly from the hive because 

 of the warmth within when the outer air is too cold for them to do so safely. If 

 bees fly at low temperatures (45 degrees to 50 degrees F.), it is an indication 

 that they need a flight because of an accumulation of feces from poor wintering 

 and does not at all indicate too high an inside temperature because of too much 

 packing. In conclusion, the beekeeper can not apply too much insulating ma- 

 terial to a hive. 



If has been found that even with abundant insulation, the temperature 

 within the hive and outside the cluster is greatly reduced if the packing case is 

 exposed to wind. During the winter 1914-15 a record was kept of wind velocity 

 directly over a heavily packed case (with entrance % inch by 8 inches), and 

 it was found that a wind with a velocity of 20 miles per hour directly on the 

 case reduces the temperature within the hives practically to that observed 

 in an unprotected hive. The beneficial efi'ects of the insulation were therefore 

 nullified and the proper temperature within the hive was not regained for sev- 

 eral days unless the outer temperature rose considerably. Beekeepers have 

 long emphasized the importance of protection from wind, but the results ob- 

 served were much more pronounced than was anticipated or than has ever been 

 suspected by practical beekeepers. The ideal toward which the beekeeper 

 should work is to keep his colonies during cold weather absolutely protected 

 from wind, for here again the protection can not be too great. It is entirely 

 erroneous to assume, as some have done, that such protection is not essential 

 in well-packed hives. 



There are several types of hives on the market in which the insulation is 

 built in, to be retained throughout the year. There is no objection to the 

 packing in the summer, except that such hives are not convenient for moving 

 and in some other manipulations. Insulation in commercial double-walled hives 

 is by means of air spaces or insulation, such as sawdust, chaff', broken cork, or 

 shavings. These hives are better for outside wintering than single-walled 

 hives in any part of the United States, but they do not provide adequate in- 

 sulation at temperatures below about 40 degrees F. Such hives must, of 

 course, be protected from wind, or they are for the time being no better than 



1 See Department Bulletin No. 93 



