silicious deposit, which was distinctly visible at the depth of a
hundred feet below the surface. No water could be discovered, but we
could distinctly hear it gurgling and boiling at a great distance below.
Suddenly it began to rise, boiling and spluttering, and sending out huge
masses of steam, causing a general stampede of our company, driving us
to some distance from our point of observation. When within about forty
feet of the surface it became stationary, and we returned to look down
upon it. It was foaming and surging at a terrible rate, occasionally
emitting small jets of hot water nearly to the mouth of the orifice.

All at once it seemed seized with a fearful spasm, and rose with
incredible rapidity, hardly affording us time to withdraw to a safe
distance, when it burst from the orifice with terrific momentum, rising
in a column the full size of this immense aperture to the height of
sixty feet; and through and out of the apex of this vast aqueous mass
five or six lesser jets or round columns of water, varying in size from
six to fifteen inches in diameter, were projected to the marvellous
height of two hundred and fifty feet. These lesser jets, so much higher
than the main column, and shooting through it, doubtless proceed from
auxiliary pipes leading into the principal orifice near the bottom,
where the explosive force is greater. If the theory that water by
constant boiling becomes explosive when freed from air be true, this
theory rationally accounts for all irregularities in the eruptions of
the geysers.

This grand eruption continued for twenty minutes, and was the most
magnificent sight we ever witnessed. We were standing on the side of the
geyser nearest the sun, the gleams of which filled the sparkling column
of water and spray with myriads of rainbows, whose arches were
constantly changing, dipping and fluttering hither and thither, and
disappearing only to be succeeded by others, again and again, amid the
aqueous columns, while the minute globules into which the spent jets
were diffused when falling sparkled like a shower of diamonds, and
around every shadow which the denser clouds of vapor, interrupting the
sun's rays, cast upon the column, could be seen a luminous circle,
radiant with all the colors of the prism, and resembling the halo of
glory represented in paintings as encircling the head of Divinity. All
that we had previously witnessed seemed tame in comparison with the
perfect grandeur a