localities, but I know that it is wonderfully great, and that rightly
controlled it will make the space immediately under these roofs cool
instead of hot.

And this is the way to cause the heat of a burning sun to cool the
attic chamber: Make the space between the rafters on the sunny sides
of your building as smooth and unobstructed as possible. Arrange
openings into the outer air at the lower end of each, simple or
complex, according to your taste and ability. Provide also means for
closing the same in cold weather. Be sure that these spaces, or flues,
are enclosed either by lath and plaster, or by smooth boards, quite to
the highest part of the roof, whether your rooms are finished to the
top or not,--and provided with an abundant outlet at the top. This may
also be as simple as the dorsal breathing-holes of a tobacco barn,
gorgeously imposing as an Oriental pinnacle, or it may be a part of
the chimney; only let it be at the very summit, ample, and so arranged
that an adverse wind shall not prevent the egress of the rising
currents of air. Mind this, too; it is by no means the same thing to
let these flues open into a loft over the attic rooms, with windows in
gables or other outlet.

Now, do you not see that as soon as the sun has warmed the flues,
there will be a stiff breeze blowing, not over the roof, but really
between the roof and the house, and the hotter the sun the stiffer the
breeze; in the words of one who has tried it,--"a perfect hurricane."
That is, the lath and plaster, or sheathing, which forms the inner
roof, is shaded by a canopy of slate, shingles, or tin, and fanned by
a constant breeze as cool at least as the outer air. But we can do
vastly better than that. Instead of opening the lower ends of these
flues to the outer air, they may be extended wherever the needs of the