Fig. 3.—An apiary packed for winter in four-colony cases such as are used in the Bureau of Entomology apiary.
A tunnel ([fig. 2, a]) is also needed through which the bees may pass on warm days and to permit ventilation. This is best made of two boards, one the width of the packing (e. g., 6 inches) and the other this width loss the extension of the bottom board. In most cases this extension is 2 inches, so the lower board will be 4 inches wide. These are held apart by strips three-eighths of an inch thick. This is the height of the usual hive entrance in winter, and the passage between the boards is therefore the same height as the hive entrance. In order that the tunnel may not get out of alignment, these strips are continued back, as shown in the figure, and these projections extend into the hive entrances at the corners. The arrangement for keeping alignment at the outer edge is discussed under "The entrance" ([p. 13]).
SINGLE OR DOUBLE CASES.
For those having only a few colonies, it is not always convenient to build cases for colonies in groups of four. It is not necessary to give dimensions in detail for those having a few colonies, however, for they will usually wish to use whatever they have at hand. It is often possible to arrange a heavy wooden box, such as those used for shipping dry goods ([fig. 4]), so as to make a winter case for one colony which will answer every purpose. It is, of course, necessary that the salient feature of a good winter case be preserved. If the arrangement of the apiary makes it inconvenient to have the colonies in groups of four throughout the year, it is quite possible to make good cases for two colonies. Anything other than the four-colony case, however, will probably cost more per colony, or if too many colonies are put into larger cases there may be trouble from other causes, as from drifting.
Fig. 4.—An improvised winter case for one colony.