regular spasmodic jets, the pulsations occurring once in ten or twelve seconds. The sides and mouth of this cavern are covered with a dark green deposit, some of which we have taken with us for analysis. About two hundred yards farther on is another geyser, the flow of which occurs about every six hours, and when the crater is full the diameter of the surface is about fourteen feet, the sides of the crater being of an irregular funnelshape, and descending at an angle of about forty-five degrees. At the lowest point at which we saw the water it was about 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.