Borealis._

While east and west are gorgeous with sunrise and sunset, the north
is often more glorious with its aurora borealis. We remember that
all worlds have weird and inexplicable appendages. They are not
limited to their solid surfaces or their circumambient air. The
sun has its fiery flames, corona, zodiacal light, and perhaps a
finer kind of atmosphere than we know. The earth is
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not without its inexplicable surroundings. It has not only its
gorgeous eastern sunrise, its glorious western sunset, high above
its surface in the clouds, but it also has its more glorious northern
dawn far above its clouds and air. The realm of this royal splendor
is as yet an unconquered world waiting for its Alexander. There are
certain observable facts, viz., it prevails mostly near the arctic
circle rather than the pole; it takes on various forms--cloud-like,
arched, straight; it streams like banners, waves like curtains in
the wind, is inconstant; is either the cause or result of electric
disturbance; it is often from four hundred to six hundred miles
above the earth, while our air cannot be over one hundred miles.
It almost seems like a revelation to human eyes of those vast,
changeable, panoramic pictures by which the inhabitants of heaven
are taught.

[Illustration: Fig. 55.--The Aurora as Waving Curtains.]

Investigation has discovered far more mysteries than it has explained.
It is possible that the same cause that produces sun-spots produces
aurora in all space, visible in all worlds. If so, we shall see
more abundant auroras at the next maximum of sun-spot, between
1880-84.

_The Delicate Balance of Forces._

A soap-bubble in the wind could hardly be more flexible in form
and sensitive to influence than is the earth. On the morning of
May 9th, 1876, the earth's crust at Peru gave a few great throbs
upward, by the action of expansive gases within. The sea fled,
and returned in great waves as the land rose and fell. Then these
waves fled away over the great mobile surface, and in less than
five hours they had covered a space equal to half of Europe. The
waves ran out to the Sandwich Islands, six [Page 145] thousand
miles, at the rate of five hundred miles an hour, and arrived there
thirty feet high. They not only sped on in straight radial lines,
but, having run up the coast to California, were deflected away into
the former series of waves, making the most complex undulations.
Similar beats of the great h