To return, however, to the subject of our present section. During the early period of Huber's investigations he prosecuted them by means of single-comb hives, which allow of each side of the comb being examined. He found, however, that there was one important defect. The bees could not in these hives cluster together, which is their natural method of withstanding the effects of a reduced temperature. Huber hit upon the ingenious expedient of combining a number of single-comb frames, so as to form one complete hive, which could be opened, in order to expose any particular comb, without disturbing the rest. From the manner of the opening and closing of this hive it has generally been called the "Leaf or Book Hive." The division separating each comb is joined both back and front with "butt hinges," fastened with a movable pin, on withdrawing which, at both sides, each comb and the bees on it may be inspected as easily as if in a single-comb hive. Huber's leaf hive is thus in appearance as if several ordinary "History of England" chess-boards were set up on end together; but each single portion is distinct, instead of there being any coupling of twos. The floor-board on which the hive stands is larger than the hive when closed, so as to allow of its being opened freely at any particular "volume." An entrance-way for the bees is hollowed out of the floor-board as in other hives. There is a glass window in each end of the hive, which is provided with a shutter. There is, however, one serious objection to Huber's hive, which, though not noticed by him or his careful assistant, has prevented its general use--that is, the difficulty there is in closing it without crushing some of the bees--a catastrophe which, by exasperating their comrades, is certain to interfere with any experiments. There is no such risk in the bar-and-frame hive, whilst in it every facility possessed by Huber's is retained.