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
is accompanied by the discharge of an immense volume of steam, which at
once shuts off all view of the inside of the crater; but sometimes,
during the few seconds intervening between the pulsations, or when a
breeze for a moment carries the steam to one side of the crater, we can
see to the depth of thirty feet into the volcano, but cannot often
discover the boiling mud; though occasionally, when there occurs an
unusually violent spasm or concussion, a mass of mud as large in bulk as
a hogshead is thrown up as high as our heads, emitting blinding clouds
of steam in all directions, and crowding all observers back from the
edge of the crater. We were led to believe that this volcano has not
been long in existence; but that it burst forth the present summer but a
few months ago. The green leaves and the limbs of the surrounding forest
trees are covered with fresh clay or mud, as is also the newly grown
grass for the distance of 180 feet from the crater. On the top branches
of some of the trees near by--trees 150 feet high--we found particles of
dried mud that had fallen upon the high branches in their descent just
after this first outburst, which must have thrown the contents of the
volcano as high as 250 or 300 feet. Mr. Hauser, whose experie