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modes of ventilation that our cause has most to fear. Only one quaint
speculation may be mentioned. It is quite certain that in the heats of
India, air is not cooled by fanning, nor is it cooled judiciously by
damping it. Professor Piazzi Smyth last year suggested this idea: Compress
air by a forcing-pump into a close vessel, by so doing you increase its
heat, then suddenly allow it to escape into a room, it will expand so much
as to be cold, and, mixing with the other air in the apartment, cool the
whole mass. This is the last new theory, which has not yet, I think, been
tried in practice.

Now, physical ventilation--that which affects to imitate the processes of
nature--is a more dangerously specious business. Its chief agent is heat.
In nature, it is said, the sun is Lord High Ventilator. He rarefies the
air in one place by his heat, elsewhere permits cold, and lets the air be
dense; the thin air rises, and the dense air rushes to supply its place;
so we have endless winds and currents--nature's ventilating works. It is
incredible that sane men should have thought this system fit for
imitation. It is a failure. Look at the hot department, where a traveler
sometimes has to record that he lay gasping for two hours upon his back,
until some one could find some water for him somewhere. Let us call that
Africa, and who can say that he enjoys the squalls of wind rushing toward
the desert? Let us think of the Persian and the Punic wars, when fleets
which had not learned to play bo-peep with ventilating processes, strewed
Mediterranean sands with wrecks and corpses. Some day we shall have these
mimics of Dame Nature content with nothing smaller than a drawing-room
typhoon to carry off the foul air of an evening party; dowagers' caps,
young ladies' scarfs, cards, pocket-handkerchiefs, will whirl upon their
blast, and then they will be happy. Now their demands are modest, but they
mean hurricanes rely upon it; we must not let ourselves be lulled into a
false security.

A fire, they say, is in English houses necessary during a large part of
the year, is constant during that season when we are most closely shut up
in our rooms. The fire, they say, is our most handy and most efficacious
ventilator. Oh, yes, we know something about that: we know too well that
the fire makes an ascending current, and that the cold air rushes from our
doors and windows to the chimney, as from surrounding countries to the
burning desert. We know t