Indeed, to one looking down into its clear depths, it seemed like a fairy palace. The same jelly-like substance or pulp to which I have before alluded covers a large area with the various shades of light red and green. The surface yields to the tread like a cushion. It is about two inches in thickness, and although seldom so tenacious as to hold together, yet it may be taken up in quite large masses, and when it becomes dry it is blown about by the wind, like fragments of variegated lichens. [From this description of the hot springs of the region we proceed to an account of its marvellous geyser phenomena.] We camped the evening of August 5 in the middle of the Upper Geyser Basin, in the midst of some of the grandest geysers in the world. Colonel Barlow and Captain Heap, of the United States Engineers, were camped on the opposite side of the Fire-Hole. Soon after reaching camp a tremendous rumbling was heard, shaking the ground in every direction, and soon a column of steam burst forth from a crater near the edge of the east side of the river. Following the steam, arose, by a succession of impulses, a volume of water, apparently six feet in diameter, to the height of two hundred feet, while the steam ascended a thousand feet or more. It would be difficult to describe the excitement which attended such a display. It is probable that if we could have remained in the valley several days, and become accustomed to all the preliminary warnings, the excitement would have ceased, and we could have admired calmly the marvellous ease and beauty with which this column of hot water was held up to that great height for the space of twenty minutes. After the display is over the water settles down in the basin several inches, and the temperature slowly falls to 150 deg.. We called this the "Grand Geyser," for its power seemed greater than any other of which we obtained any knowledge in the valley. [After describing more particularly the peculiarities of the Grand Geyser and the smaller neighboring geysers, Dr. Hayden gives us an enthusiastic pen-picture of a beautiful type of springs.]