Advancing more boldly, he found himself near
the edge of a deep pit.

The pit was almost perfectly round and had a diameter of about
ten feet. So far as Dick could judge, it was about forty feet
deep and entirely empty. It looked like a huge well dug by the
hand of man.

While Dick was gazing at the pit, an extraordinary and terrifying
thing happened. The earth under his feet began to shake. At
first he could not believe it, but when he steadied himself and
watched closely, the oscillating motion was undoubtedly there.
It was accompanied, too, by a rumble, dull and low, but which
steadily grew louder. It seemed to Dick that the round pit was
the center of this sound.

Despite the quaking of the earth, he ventured again into the open
space and saw that the pit had filled with water. Moreover, this
water was boiling, as he could see it seething and bubbling. As
he looked, clouds of steam shot up to a height of two or three
hundred feet, and Dick, in alarm, ran back to the bushes. He
knew that this was the column of vapor he had first seen from a
distance, but he was not prepared for what followed.

There was an explosion so loud that it made Dick jump. Then a
great column of water shot up from the boiling pit to a height of
perhaps fifty feet, and remained there rising and falling. From
the apex of this column several great jets rose, perhaps, three
times as high.

The column of hot water glittered and shimmered in the sun, and
Dick gazed in wonder and delight. He had read enough to
recognize the phenomenon that he now saw. It was a geyser, a
column of hot water shooting up, at regular intervals and with
great force, from the unknown deeps of the earth.

As he gazed, the column gradually sank, the boiling water in the
pit sank, too, and there was no longer any rumble or quaking of
the earth. Dick cautiously approached the pit again. It was as
empty as a dry well, but he knew that in due time the phenomenon
would be repeated. He was vastly interested, but he did not wait
to see the recurrence of the marvel, continuing his way down the
valley over heaps of crinkly black slag and stone, which were
age-old lava, although he did not know it, and through groves of
pine and ash, aspen, and cedar. He saw other round pits and
watched a second geyser in eruption. He saw, too, numerous hot
springs, and much steamy vapor floating about. There were also
mineral springs and springs of the clearest and pures