The observatory-hive, as here exhibited in Fig. 1, consists of two apartments--an upper one and a lower one. The upper one, (marked a. b. c. d. e. e.) is properly the observatory-hive, and may be called the summer pavilion; the lower one, (marked g.) may be termed the winter-pavilion. Of this winter-pavilion but little need be said, except that it is an octagonal box, in size, in substance, and in every respect, similar to the octagon-part of the _inverted-hire_ described in the last chapter; save only that its top must not be cut away, as is there directed to be done. At present let us suppose this top to be a perfect plane--an entire surface, without any aperture of any sort to form a passage for the Bees from and through it down into the pavilion below ; farther let us suppose an alighting-board of the usual size to be fixed in front, and on a level with this floor or top ; then the quere will be --how from the same front-entrance, the Bees are to have a passage both'into the observatory-hive above, and into the winter-pavilion below? The difficulty is--to get a convenient passage into the summer-pavilion, because the whole of that pavilion is made to turn round on the shoulder of an upright shaft, through which that the passage for the Bees must of necessity be made, and which does not admit of a bore of above an inch in diameter. As, however, this narrow, perpendicular passage is of no great length, (it need not be more than three inches) many thousands of Bees will, in the course of a few minutes, if necessary, make their egress and regress through it without incommoding one another. That this rather intricate part--the construction of this passage-work--may be fully comprehended, I will endeavour to illustrate it by references to a well known article, now standing on the table on which I am writing. It is a telescopic candlestick, the pedestal of which covers a square space upon my table, each side of which superficial square is three inches. Now suppose this candlestick was screwed or glued to the centre of the plain, tabular top of the octagon (g) having one of its sides parallel to that side of the floor to which the alighting-board is attached. Next, suppose _that_ side of the candlestick to be cut away so as to form an entrance into the interior of the pedestal, two inches in front and half an inch in height; and let there be a covered-way of this height, from the opened side of the pedestal to the front-entrance of the hivc : then, if the front-entrance be six inches wide, the Bees on coming in will enter this covered-way, which from six inches narrows to three at the part where they enter the pedestal, and begin to ascend the perpendicular passage which leads through it and through the upright shaft of the candlestick into the--at present _supposed_ apartment above. The top-part of a telescopic candlestick may be turned round at pleasure ; consequently, if the pedestal be fixed and made immoveable, the top, and whatever may be upon that top and fastened to it, may be moved round notwithstanding : this is what we particularly want in the construction of an observatory-hivc, and must, therefore, be particularly attended to. A piece of clean, close-grained wood--becch, elder, mahogany, or any other firm wood--made much in the shape of our telescopic candlestick, but of not more than two inches and a half in height, with a bore through it of an inch in diameter, and turned, that is, wrought in a lathe, so that an inch of the top-part may enter into, and neatly fit, the cap) fixed round the inch bore at the centre of the bottom-frame of the upper pavilion (Fig 2), and which cap is representedby the moveable top of the candlestick, is, as wellas I can describe it, the pedestal to support the observatory-hive,--is, with the cap just mentioned, the compound, or double-hinge upon which that hive is turned round,--and is also the Bee-way into that hive.