of one hundred feet. Around this crevice or mouth the sediment is piled
in many capricious shapes, chiefly indented globules from six inches to
two feet in diameter. Little hollows in the crust filled with water
contained small white spheres of tufa, of the size of a nutmeg, formed
as it seemed to me around some nuclei.[Z]

We gave such names to those of the geysers which we saw in action as we
think will best illustrate their peculiarities. The one I have just
described General Washburn has named "Old Faithful," because of the
regularity of its eruptions, the intervals between which being from
sixty to sixty-five minutes, the column of water being thrown at each
eruption to the height of from eighty to one hundred feet.

The "Fan" has a distorted pipe from which are projected two radiating
sheets of water to the height of sixty feet, resembling a feather fan.
Forty feet from this geyser is a vent connected with it, two feet in
diameter, which, during the eruption, expels with loud reports dense
volumes of vapor to the height of fifty feet.

[Illustration: OLD FAITHFUL. NAMED BY GENERAL WASHBURN.]

The "Grotto," so named from the singularly winding apertures penetrating
the sinter surrounding it, was at rest when we first discovered it.
Externally it presented few indications of its character as a geyser.
Private Williamson, one of our escort, crawled through an aperture and
looked into the discharging orifice. When afterwards, he saw it belching
forth a column of boiling water two feet in diameter to the height of
sixty feet, and a scalding stream of two hundred square inches flowing
from the cavern he had entered a short time before, he said that he felt
like one who had narrowly escaped being summarily cooked.

The "Castle" is on the summit of an incrusted elevation. This name was
given because of its resemblance to the ruins of some old tower with its
broken down turrets. The silicious sinter composing the formation
surrounding it takes the form of small globules, resembling a ripe
cauliflower, and the massive nodules indicate that at some former period
the flow of water must have been much larger than at present. The jet is
sixty feet high by four feet in diameter, and the vent near it, which is
in angry ebullition during the eruption, constantly flows with boiling
water.

One of the most wonderful of the springs in this basin is that of
ultra-marine hue directly in front of the "Castle" geyser. It is nearly