68 
BEES AND BEE-KEEPING. 
presence, after it has reached the heat of the hand, 
will in no way affect temperature. It is true that, 
in winter, the part of the runner nearest the cluster 
will be slightly warmer than the rest, and that it 
will tend somewhat to equalise temperature ; but the 
conduction from this cause is so infinitesimally small 
as to be practically nil. Both tin (iron) and zinc 
stand low down as conductors amongst the metals, 
and, in addition, their capacity for heat is not more 
than a tenth of that of water ; or it may be stated, for 
the benefit of those unacquainted with the scientific 
bearings of the matter, that it would require as much 
heat to raise i oz. of water through any number of 
degrees, as would be absorbed by lo oz. of either of 
these metals. Thus, then, syrup holding 31b. of water, 
and given as food at the heat of the external air, 
would abstract more heat from the cluster of bees 
than Jcwt. of zinc placed cold in their midst. But 
metal runners, while hanging frames are used, may 
be safely left to take care of themselves ; let us, 
therefore, see how we may obviate the propolisation 
on the ear, which the use of the quilt now occasions. 
The Author has had made, for experimental pur- 
poses, some reversible — or, more correctly, invertible* — 
frames, which have led to a solution of the difficulty, 
by the substitution of a thin iron lug (z 7 , B, Fig. 22) 
for the wooden one. For this purpose, nothing 
seems to excel hoop-iron No. ig, Jin. wide. This 
is thin enough to be bent to shape while cold, and 
* These frames permit of the bottom of the contained comb being 
made the top, and so should be called invertible. The word “reversible,” 
implying that the front may be turned to the back, is here inapplicable, 
and should be discontinued. 
