Near this magnificent spring is a hill of silica with a spring 150 feet in diameter on its summit. It is known as the Cauldron. The water boils up in the centre, and overflows with such uniformity on all sides as to form a succession of ornamental steps, from one to three inches in height, just as water would freeze in flowing down a gentle declivity. It has the same transparent clearness, the same brilliancy of coloring, as the spring above described, but the hot steam and the thinness of the rim prevented an approach near enough to observe its depth, or ascertain its temperature, except at one edge, where it was 180°. The average temperature of twenty of the springs of this group was 184°. About a mile below this group, on the west side of the river, are four small lakes, with quiet surfaces and water as blue as the sky. One of them is nearly half a mile in length. Their water is cold at the present time, but their basins give indications of their having once been enormous hot springs. A mile or so further down the river is a group of a hundred or more important springs besides a countless number of unimportant and dead springs, covering a space of nearly a square mile. Only a few of them can be specially noticed here. One, on the right bank of the river, is called the Conch Spring, from the resemblance of its basin to a shell, eight feet by ten. A little below the Conch Spring, on the very margin of the river, is a fine geyser, which has built for itself a crater three feet high, with a shell a foot thick. The inside of the crater is about six feet in diameter. The water is in constant agitation; sometimes it will boil up so violently as to throw the entire mass up four feet, and then it will die down so as to boil like a caldron. The water is perfectly clear, and the overflow forms a stream six inches wide and two inches deep, passing down the sides of the crater and thence into the river along a most exquisitely decorated channel. The entire surface of the crater is covered with pearl-like beads, formed by the spray. A section of the crater shows it to have been built up very slowly, in thin laminæ. Another spring has a crater like a horn, about a foot in diameter at the top and six feet at the base. It is called the Horn Geyser. It is in constant ebullition, and has the same ornamentations as the one just described. A spring on a level with the river has an enormous square basin, thirty feet across, of unknown depth. It is called the Bath Spring. A little below is another basin of wonderful beauty, called the Cavern. The water issues from several apertures beneath the crust near the margin of the river. The basin itself is fifteen by twenty feet, and twenty feet deep. Nothing can exceed the transparent clearness of the water; the slightest object is reflected in its clear depths, and the bright blue tints are indescribable. Mud springs are also numerous and important in this group. As usual, they are of all sizes, from an