The connection between Sound and the atmosphere is an important one.
The air is a conductor of sound, and in some conditions one of the
best. A bell rung in an exhausted receiver gives no sound. In the
Arctic regions ordinary conversations have been distinctly heard for
the distance of a mile and a half.

All that we have thus far said in this article bears directly, in some
form or other, on another of the great features of Meteorology, one of
its great objects, and an unceasing topic,--namely, Climate.

The term Climate, in its general sense, indicates the changes and
condition of the atmosphere, such as we have been considering. It has
something to do with all of them; it is not entirely controlled by
any. Thus, places having the same mean annual temperature often differ
materially in climate. In some (we quote Mrs. Somerville) the winters
are mild and the summers cool, whereas in others the extremes of heat
and cold prevail.

Climates are not found coincident with lines of latitude; they are
quite as often found parallel to lines of longitude. If you connect
the extreme points of the mean annual temperatures by a line passing
round the earth, you have a zone, but never a true circle. The curves
are longitudinal.

Climate is dependent on temperature, winds, the elevation of land,
soil, ranges of mountains, and proximity of bodies of water; and it is
also the expression, if we may so term it, of the changes in the
atmosphere sensibly affecting our organs. Humboldt refers it to
humidity, temperature, changes in barometric pressure, calmness or
agitation of the air, amount of electric force, and transparency of