tex) does not derange
every place alike, but _skips_ over large tracts of longitude in its
progress westward. We speak here of the immovable axis of the vortex as
in motion; in reality it is the rotation of the earth which brings every
meridian under its influence in some latitude once every twenty-four
hours. The centre of greatest derangement forms the nucleus, towards
which the surface currents, under certain restrictions, flow. The
strongest current will, however, usually be from the south, on account
of the inclination of the axis of the vortex to the surface of the
earth.[8] These currents continuing onwards by their vires inertiae,
according to the first law of motion, assist somewhat in conveying the
warm surface wind, loaded with moisture, into the region of cloud; and
the diminution of temperature causes the condensation of large masses of
vapor, according to Hutton's views; and the partial vacuum thus
produced, causes a still greater intermingling. But we have already
shown that this is not the sole cause, nor is it ever more than
partially accomplished. The ether of the lower atmosphere, and of the
crust of the earth, is disturbed, and rushes towards the rarefied axis
from the surface, and with the temperature of the surface, thus
conveying the surface atmosphere, in a measure, along with it. In the
upper regions, this ether (or electric fluid) cools down, or parts with
some of its heat, to the air of those regions, and, by its great
specific caloric, necessarily and unduly increases the temperature of
the air. This, by its expansion and ascension will cause a further
influx from below, until the upper atmosphere becomes loaded with vapor.
In twelve hours, at least, a reaction must take place, as that part of
the earth's surface is carried six or seven thousand miles from the
axis, where the ether is more dense. This in turn descends to the
surface, carrying with it the temperature of space, at least 60d below
zero; a great condensation must follow; local derangements of the
electric equilibrium in the centre of large clouds, when the
condensation is active, must now take place, while partially
nonconducting masses intervene, to prevent an instantaneous restoration
of the equilibrium, until the derangement is sufficient to cause the
necessary tension, when all obstacles are rent asunder, and the ether
issues forth, clothed in the power and sublimity of the lightning. It is
a fearfully-energetic fluid, and, wh