e 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
house require, or its construction will allow.

Let me remind you, under the head of general principles, that there is
no such thing as "suction." Of course, you know it when you stop to
think, but bear it in mind, and wherever the motive-power seems to be
applied on which you rely to lift the column of air, remember that if
raised at all it must be raised from the bottom. Maybe you will
discover room for a moral here.

This summer ventilation is simple enough, and relates rather to
comfort than to health. The great question in building, for New
England and similar climates, is, indeed, how to keep our houses warm,
and, without great expenditure of fuel, have a constant change of air.
As you suggest, we have learned that wood costs eight or ten dollars a
cord instead of the mere labor of cutting and hauling; hence we have
shut the mouths of the old-time fireplaces, mouths that it would cost
a fortune to feed. We find the value of building-timber increasing
every year; so we make thinner walls, lined outside and inside with
paper, and