First, the frame of one side, as before stated, is put together, A B C D (Fig. 1), then that of the opposite side, E F G H, the various corners being mortised into one another (Fig. 2). Then the remaining parts of the frame having been got ready piece by piece, the whole may be set up. The two iron stays between each couple of upright rafters must on no account be omitted; nor yet the galvanized iron squares, similar to those used by shop-keepers to support their window-shelves, which will be found most useful to strengthen the angles.
Fig. 3.
Now get the mason to come with his cement and some bricks, and build up on the selected site a level foundation for the house to rest on, spreading a layer of cement along the top of the upper course of bricks, to which the base of the frame-work (which must be lifted on to it while it is moist) will adhere. Then, to give additional stability, and lessen the risk of the house being lifted or shifted by a gale (for, being open in front and sides, it will offer, like the inside of an open umbrella, far greater resistance to the wind than would be the case if glazed as a greenhouse is), an inner line of bricks is next cemented against the side of the bottom rafters all round, and flush with their surface, as seen at Fig. 3. Lastly, when the floor has been paved with bricks, the mason's job is finished.
Fig. 4.
Fig. 5.
Now comes the roof. This is made to play out widely for two purposes: to give our aviary a somewhat ornamental appearance, and also to carry the drip well clear of the walls and wire netting. First of all, the boards, B (Fig. 4), must be nailed on, planed surface downward, to form a smooth ceiling; then the whole is covered with strips of stout canvas, A, overlapping one another. The ends of the canvas are fastened tightly under the eaves, and the exposed selvedge of one strip, with the selvedge of the next beneath, is properly tacked to the wood. Finally the top piece, C, and the narrow strips of wood, B (Fig. 5), being securely nailed on over the canvas, the roof is complete; and when painted with light lead-color, it will be perfectly water-proof, and have the appearance, without the weight, of a real leaden covering.
