he atmosphere at such times is too dry to make a violent
storm, and there is a silent restoration of the equilibrium, by the
ether passing through the dry atmosphere, without meeting any
condensable vapor, and becoming luminous on account of the greater
resistance of the air when unmixed with vapor. We thus see also the
connection between the aurora and the linear cirri, and we have a
triumphant explanation of the fact, that when the observer is north of
the northern limit of the vortices, he sees the aurora to the south and
not to the north; for, to see it to the northward, he would have to see
it in the same latitude as it appears in the south, and, consequently,
have to see across twice the complement of the latitude. We thus see,
also, why the temperature falls after an aurora; for, the passage of
electricity in any shape, must have this effect on account of the great
specific caloric of this fluid. We see, also, why the aurora should be
more frequent where the magnetic intensity is greatest and be
consequently invisible at the equator, and why the magnetic needle is so
sensibly affected at the time of its occurrence. We may, perhaps, here
be allowed to allude to another phenomenon connected with terrestrial
magnetism and electricity.

EARTHQUAKES.

The awful and destructive concussions which sometimes are produced at
great depths beneath the surface of the soil, would seem to indicate
that no force but that of electricity is adequate to account for the
almost instantaneous desolation of wide tracts of the earth's surface.
But we do not mean to say that the action of the terral vortices,
combined with the internal conditions of our planet, is the only cause;
although it is far from improbable that the same activity of the ether,
which generates through these vortices, the full fury of the hurricane
in the tropics, may be simultaneously accompanied by a _subterranean_
storm. And physicists are too rash to reject the evidence on which the
connection of the phenomena rests.

In the extract given by Colonel Reid, in his "Law of Storms," from Sir
George Rodney's official report of the great hurricane of 1780, it is
stated, that, "Nothing but an earthquake could have occasioned the
_foundations_ of the strongest buildings to be rent; and I am convinced
that the violence of the wind must have prevented the inhabitants from
feeling the earthquake which certainly attended the storm."[33] Again,
in the Savannah-la-Mar hu