ry interesting in its effects, and the noise it makes is quite
peculiar, not unlike a subdued hiss or a badly executed stage-whisper.
Mixed among the white substance is a quantity of silicious clay of all
sorts and conditions of color. This produces a variation in the
appearance, but is merely in addition to what is otherwise marvelous in
the extreme. Pearl gray, with terra cotta, red and green tints is the
basic color of this boiling, seething mass, which seems to be
continually at unrest and in a course of worry.

The Excelsior Geyser is the most conspicuous feature of the Midway
Basin, a collection of hot springs and pools. They are situated in the
Midway Basin, and were originally called Cliff Caldron. Excelsior Geyser
is in a continual state of anarchy, without law, government or
regulation. It does just as it likes and when it likes. It seldom
performs when wanted to, but when it does break out into a condition of
fermentation, the effect is very magnificent. As one writer puts it, the
beauties and exhibitions of this geyser are as far superior to those of
all the others as the light of the sun seems to that of the moon.

The geyser was for years regarded as the grandest spring in the park,
before its exceptionally great features prevailed or became apparent. In
the years 1881-82, the eruptions from this geyser became so terrific
that it spouted water as high as 250 feet, and converted the generally
inoffensive Firehole River into a torrent of storming water. Rocks of
large size and heavy enough to be very dangerous were hurled headlong
from within the mysterious confines of the earth, and were dashed around
in all directions. For miles the terrific noise could be heard, and
people who had been waiting for a phenomenon of this character, hurried
across country to witness it. It is only now and again that a phenomenon
of this kind is repeated, and the most skillful geologists are unable to
give us any adequate forecasts as to when the next performance will take
place.

Rehearsals seem always in progress. Vast masses of steam rise from the
crater or hole. Many people crowd to the edge of the basin and strive to
penetrate into the mysteries of subterranean happenings. The day may
come when some scientific method of seeing through smoke and steam and
enduring scalding heat without difficulty may be devised. Until then the
mystery must remain unsolved.

In exact contrast with the irregular and spasmodic action of th