"The region was filled with boiling springs and craters. Two hills, each 300 feet high, and from a quarter to half a mile across, had been formed wholly of the sinter thrown from adjacent springs--lava, sulphur, and reddish-brown clay. Hot streams of vapor were pouring from crevices scattered over them. Their surfaces answered in hollow intonations to every footstep, and in several places yielded to the weight of our horses. Steaming vapor rushed hissingly from the fractures, and all around the natural vents large quantities of sulphur in crystallized form, perfectly pure, had been deposited. This could be readily gathered with pick and shovel. A great many exhausted craters dotted the hill-side. One near the summit, still alive, changed its hues like steel under the process of tempering, to every kiss of the passing breeze. The hottest vapors were active beneath the incrusted surface everywhere. A thick leathern glove was no protection to the hand exposed to them. Around these immense thermal deposits, the country, for a great distance in all directions, is filled with boiling springs, all exhibiting separate characteristics. "The most conspicuous of the cluster is a sulphur spring twelve by twenty feet in diameter, encircled by a beautifully scolloped sedimentary border, in which the water is thrown to a height of from three to seven feet. The regular formation of this border, and the perfect shading of the scollops forming it, are among the most delicate and wonderful freaks of nature's handiwork. They look like an elaborate work of art. This spring is located at the western base of Crater Hill, above described, and the gentle slope around it for a distance of 300 feet is covered to considerable depth with a mixture of sulphur and brown lava. The moistened bed of a small channel, leading from the spring down the slope, indicated that it had recently overflowed. "A few rods north of this spring, at the base of the hill, is a cavern whose mouth is about seven feet in diameter, from which a dense jet of sulphurous vapor explodes with a regular report like a high-pressure engine. A little farther along we came upon another boiling spring, seventy feet long by forty wide, the water of which is dark and muddy and in unceasing agitation.