e of the air,
while the central mass hurries downward by its concentrated weight.
The general appearance is that of numerous spearheads with serrated
edges, feathered with light, thrust from some celestial armory into the
writhing pool of agonized waters below. In the geyser one gets this
effect both in the ascending and in the descending flood.

Four times that first night dear old Splendid lured me from my bed to
watch her Titanic play in the full light of the moon. During all this
time not a hot spring ceased its boiling, nor a smaller geyser its
wondrous play, for this gigantic outburst of power that might well have
absorbed every energy for a mile around. Obviously they have no
connection. Then my beloved Splendid settled into a three-days' rest.

These are the essential facts of geyser display. There are very many
variations of performance in every respect, I have seen over twenty
geysers in almost jocular, and certainly in overwhelmingly magnificent,
activity.

"To him who in the love of nature holds
Communion with her visible forms, she speaks
A various language."

WHAT ARE THE CAUSES?

What is the power that can throw a stream of water two by six feet over
the tops of the highest skyscrapers of Chicago? It is heat manifested
in the expansive power of steam. Scientists have theorized long and
experimented patiently to read the open book of this tremendous
manifestation of uncontrollable energy. At first the form and action
of a teakettle was supposed to be explanatory. Everyone knows that
when steam accumulates under the lid it forces a gentle stream of water
from the higher nozzle. This fact was made the basis of a theory to
account for geysers by Sir George Mackenzie in 1811. But to suppose
that nature has gone into the teakettle manufacturing business to the
extent of thirty such kettles in a space of four square miles was seen
to be preposterous. So the construction theory was given up.

But suppose a tube (how it is made will be explained later), large or
small, regular or irregular, to extend far into the earth, near or
through any great source of heat resulting from condensation,
combustion, chemical action, or central fire. Now suppose this tube to
be filled with water from surface or subterranean sources. Heat
converts water, under the pressure of one atmosphere, or fifteen pounds
to the square inch, into steam at a temperature of two hundred and
twelve degrees. But under