expense
would be less by one half.

[14] The observations to test the temperature of the Protector were made
in Greenfield, Massachusetts, in latitude 42 deg. 36 min.

CHAPTER IX.

VENTILATION OF THE HIVE.

If a populous hive is examined on a warm Summer day, a considerable
number of bees will be found standing on the alighting board, with their
heads turned towards the entrance, the extremity of their bodies
slightly elevated, and their wings in such rapid motion that they are
almost as indistinct as the spokes of a wheel, in swift rotation on its
axis. A brisk current of air may be felt proceeding from the hive, and
if a small piece of down be suspended by a thread, it will be blown out
from one part of the entrance, and drawn in at another. What are these
bees expecting to accomplish, that they appear so deeply absorbed in
their fanning occupation, while busy numbers are constantly crowding in
and out of the hive? and what is the meaning of this double current of
air? To Huber, we owe the first satisfactory explanation of these
curious phenomena. These bees plying their rapid wings in such a
singular attitude, are performing the important business of
_ventilating_ the hive; and this double current is composed of pure air
rushing in at one part, to supply the place of the foul air forced out
at another. By a series of the most careful and beautiful experiments,
Huber ascertained that the air of a crowded hive is almost, if not
quite, as pure as the atmosphere by which it is surrounded. Now, as the
entrance to such a hive, is often, (more especially in a state of
nature,) very small, the interior air cannot be renewed without resort
to some artificial means. If a lamp is put into a close vessel with only
one small orifice, it will soon exhaust all the oxygen, and go out. If
another small orifice is made, the same result will follow; but if by
some device a current of air is drawn out from one, an equal current
will force its way into the other, and the lamp will burn until the oil
is exhausted.

It is precisely on this principle, of maintaining a double current by
_artificial means_, that the bees ventilate their crowded habitations. A
body of active ventilators stands inside of the hive, as well as
outside, all with their heads turned towards the entrance, and by the
rapid fanning of their wings, a current of air is blown briskly out of
the hive, and an equal current drawn in. This important office is o