seven feet in diameter on the surface. One or another of our party
watched the gradual rise of the water for four or five hours. The
boiling commenced when the water had risen half way to the surface,
occasionally breaking forth with great violence. When the water had
reached its full height in the basin, the stream was thrown up with
great force to a height of from twenty to thirty feet, the column being
from seven to ten feet in diameter at the midway height of the column,
from bottom to top. The water was of a dark lead color, and those
portions of the sides of the crater that were overflowed and then
exposed by the rise and fall of the water were covered with stalagmites
formed by the deposit from the geyser.

While surveying these wonders, our ears were constantly saluted by dull,
thundering, booming sounds, resembling the reports of distant artillery.
As we approached the spot whence they proceeded, the ground beneath us
shook and trembled as from successive shocks of an earthquake. Ascending
a small hillock, the cause of the uproar was found to be a mud
volcano--the greatest marvel we have yet met with. It is about midway up
a gentle pine-covered slope, above which on the lower side its crater,
thirty feet in diameter, rises to a height of about thirty-five feet.
Dense masses of steam issue with explosive force from this crater, into
whose tapering mouth, as they are momentarily dispelled by the wind, we
can see at a depth of about forty feet the regurgitating contents. The
explosions are not uniform in force or time, varying from three to eight
seconds, and occasionally with perfect regularity occurring every five
seconds. They are very distinctly heard at the distance of half a mile,
and the massive jets of vapor which accompany them burst forth like the
smoke of burning gunpowder.

Some of these pulsations are much more violent than others, but each one