Six miles above the upper fall we entered upon a region remarkable for the number and variety of its hot springs and craters. The principal spring, and the one that first meets the eye as you approach from the north, is a hot sulphur spring, of oval shape, the water of which is constantly boiling and is thrown up to the height of from three to seven feet. Its two diameters are about twelve feet and twenty feet, and it has an indented border of seemingly pure sulphur, about two feet wide and extending down into the spring or cauldron to the edge of the water, which at the time of our visit, if it had been at rest, would have been fifteen or eighteen inches below the rim of the spring. This spring is situated at the base of a low mountain, and the gentle slope below and around the spring for the distance of two hundred or three hundred feet is covered to the depth of from three to ten inches with the sulphurous deposit from the overflow of the spring. The moistened bed of a dried-up rivulet, leading from the edge of the spring down inside through this deposit, showed us that the spring had but recently been overflowing. Farther along the base of this mountain is a sulphurous cavern about twenty feet deep, and seven or eight feet in diameter at its mouth, out of which the steam is thrown in jets with a sound resembling the puffing of a steam-boat when laboring over a sand-bar, and with as much uniformity and intonation as if emitted by a high-pressure engine. From hundreds of fissures in the adjoining mountain from base to summit, issue hot sulphur vapors, the apertures through which they escape being encased in thick incrustations of sulphur, which in many instances is perfectly pure. There are nearby a number of small sulphur springs, not especially remarkable in appearance.