re. The floor should be of concrete or brick, and the house
should be fitted with an efficient heating apparatus from which the heat is
distributed by means of hot-water pipes. Any arrangement which would permit
the escape into the aviary of smoke or noxious fumes is to be strongly
condemned. Such a house must be well lighted, preferably by means of
skylights; but it is a mistake to have the whole roof glazed, at least half
of it should be of wood, covered with slates or tiles. Perches consisting
of branches of trees with the bark adhering should be fixed up, and, if
small birds are to be kept, bundles of bushy twigs should be securely fixed
up in corners under the roofs.

The outer part, which will principally be used during the summer, though it
will do most birds good to be let out for a few hours on mild winter days
also, should be as large as possible, and constructed entirely of
wire-netting stretched on a framework of wood or iron. If the latter
material is selected, stout gas-piping is both stronger and more easily
fitted together than solid iron rods.

If the framework be of wood, this should be creosoted, preferably under
pressure, or painted with three coats of good lead paint, the latter
preservative also being used if iron is the material selected.

[Illustration: FIG. 1.]

The wire-netting used may be of almost any sized mesh, according to the
sized birds to be kept, but as a general rule the smallest mesh, such as
half or five-eighths of an inch, should be used, as it is practically
vermin-proof, and allows of birds of any size being kept. Wire-netting for
aviaries should be of the best quality, and well galvanized. The new
interlinked type is less durable than the old mesh type, though perhaps it
looks somewhat neater when fixed.

Provision must be made for the entire exclusion of such vermin as rats,
stoats and weasels, which, if they were to gain access, would commit great
havoc amongst the birds. The simplest and most effectual method of doing
this is by sinking the wire-netting some 2 ft. into the ground all round
the aviary, and then turning it outwards for a distance of another foot as
shown in the annexed cut (fig. 1).

The outer part of the aviary should be turfed and planted with evergreen
and deciduous shrubs, and be provided with some means of supplying an
abundance of pure water for the birds to drink and bathe in; a gravel path
should not be forgotten.

Perhaps the most useful type of