THE GRAND GEYSER OF THE FIREHOLE BASIN.
Dr. Hayden describes it with equal enthusiasm.
"We camped the evening of August 5th, 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 Firehole. 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 by a succession of impulses, a column of water, apparently six feet in diameter, rose to the height of 200 feet, while the steam ascended a thousand feet or more. So steady and uniform did the force act, that the column of water appeared to be held there for some minutes, returning into the basin in millions of prismatic drops. This was continued for about fifteen minutes, and the rumbling and confusion attending it could be compared only to that of a charge in battle. It would be difficult to describe the intense 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°. We called this the Grand Geyser, for its power seemed greater than any other of which we obtained any knowledge in the valley. The are two orifices in one basin; one of them seems to have no raised rim, and is a very modest-looking spring in a state of quiescence, and no one would for a moment suspect the power that was temporarily slumbering below. The orifice is oblong, two and a half by four feet, while for the space of ten feet in every direction around it are rounded masses of silica, from a few inches to three feet in diameter, looking like spongiform corals. Nothing could exceed the crystal clearness of the water. This is the Grand Geyser. Within twenty feet of this orifice is a second one, of irregular quadrangular form, fifteen by twenty-five feet; the east side of the main outer rim of reservoir extended twenty feet beyond the large orifice. The bottom of this great reservoir is covered with thick spongiform masses, and in addition the rim is most elegantly adorned with countless pearl-like beads, of all sizes. There are several beautiful triangular reservoirs, one and one half by three feet, set around the outer sides of the rim, with numerous smaller ones, full of clear water, with hundreds of small depressions most beautifully scalloped. As we recede from the rim, the waters as they pass slowly away produce, by evaporation, broad shallow basins, with thin, elegantly colored partitions, portions of which have the form of toad-stools. When the water settles into these depressions, or flows away toward the river in numerous small channels, the wonderful variety of coloring which is so attractive to the eye is produced. The larger orifice seems to be in a state of violent agitation as often as once in twenty minutes, raising up the entire mass of water ten or fifteen feet. It is never altogether quiet. Although these two orifices are within the same rim, I could not ascertain that there is the slightest connection with each other. When the large orifice is much agitated it does not disturb the equanimity of the Grand Geyser. They both operate perfectly independently of each other. Indeed I do not know that there is a connection between any of the springs in the whole basin, though there may be in some rare cases. The Grand Geyser operated twice while we were in the basin, with an interval of about thirty-two hours; of course the displays could not be exactly periodic, but it would be an interesting study to remain several days to watch carefully the movements of such a power."
Just east of Grand Geyser is the Saw-mill, a moderate sized geyser, with three smaller ones by the side of it, all playing at the same time. From the larger a column of water is constantly shot up fifteen or twenty feet, with much the sound of the escape of steam from a pipe. The orifice is not more than six inches in diameter; but with the three smaller ones playing at the same time a great commotion is excited. Near this little group are several large boiling springs, which throw up the water in the centre from two to four feet. These are funnel-shaped, with orifices from six inches to two feet in diameter, in basins with nearly circular rims, from fifteen to forty feet in diameter. About one fourth of a mile northeast of the Castle, upon a mound thirty feet about above the river, built up of thin laminæ of silica, and rounded off, rise four chimneys of different sizes, which are geysers, though perhaps not spouting extensively at present. One is twelve inches high, nearly circular, and three feet in diameter; the second is oblong, four by six feet, with rather coarsely scolloped margins, with an aperture about fifteen inches in diameter; the third chimney is about three feet high and six feet in diameter at the base, with an orifice nearly quadrangular twelve inches across. The spongiform masses inside are covered all over with beautiful pearly beads of silica. The fourth chimney rises five feet above the mound, is ten feet in diameter at the base, with an orifice two feet across, lined inside with the spongiform masses. This has been at one time a first-class geyser, but is now fast going to decay, a beautiful ruin. The elegant bead work on the margin, and all the spongiform masses, now are falling into pieces, forming great quantities of débris around the base of the mound. There is also one boiling spring of great beauty. The orifice, which is nearly circular and beautifully scolloped around the margin, extends straight down, and the water rises within an inch or two of the margin. The water is in a state of constant agitation, boiling up two feet at times. The margin has a coating of bright cream-yellow, while all around the surface there is the most delicate and intricate embroidering, surpassing the most elaborate lace-work. Surrounding the crater is an outer reservoir four feet wide, with a white and reddish-yellow rim, while in the bottom of the reservoir is the variegated sediment which aids in giving such a wonderfully gay appearance to the spring. A stream of water flows from the spring to the river, and the channel is lined for fifty yards with the variegated sediment. Near this is another mound which rises, with laminated steps, about six feet. Dr. Hayden called it the Bathtub. It has much the shape and size of an ordinary bathing-tub, five feet by ten, beautifully scolloped around the inner margin with the spongiform or cauliflower masses of silica, the outer surface being adorned with the greatest profusion of pearly beads. The water is constantly boiling up two feet high, though but a small quantity flows from the spring. The entire valley is full of similar springs, many of these no doubt geysers whose periods of activity have never been observed. "We could not distinguish," writes Lieut. Doane, "the geysers from the other hot springs except by seeing them play, and doubtless there are many besides in the valley of great size, which we saw when quiet, and classed as boiling springs. They all vary in times, force, deposits, and color of water. The number of springs of all kinds in the valley is not less than fifteen hundred; and, with the exception of the Bluestone Springs, scarcely any two are exactly alike. Taken as an aggregate, the Firehole Basin surpasses all the other great wonders of the continent. It produces an effect on the mind of the beholder utterly staggering and overpowering. During the night we were several times awakened by the rush of steam and the hissing of the waters, as the restless geysers spouted forth in the darkness. A constant rumbling, as of machinery in labor, filled the air, which was damp and warm throughout the night."
Lieutenant Doane's suspicion that many quiet-looking springs were slumbering geysers, was speedily and grandly justified. The very next morning his company were awakened by a fearful hissing sound, accompanied by the rush of falling water. On looking out, they saw on the other side of the stream a small crater, three feet in height, with an opening 26 inches in diameter, which had scarcely been noticed on the previous day. Now it was playing a perpendicular jet to the height of 219 feet, amid great clouds of steam, and causing the ground to tremble as the heavy body of water fell with tremendous splashes upon the shelly strata below. Huge masses of rock were torn from their places and borne away into the river channel. It played thus, steadily, for ten minutes, giving time to obtain an accurate measurement by triangulation. This crater gave no notice of being a geyser, and its appearance and size, compared with others, were altogether insignificant. "We were more than ever convinced," adds Lieutenant Doane, "that continued observation would develop the knowledge of geysers in greater numbers, and perhaps of greater projectile force than any we had seen."
Crossing the river once more to the south side—that of Old Faithful and the Castle—we find another large group of springs, the chief of which is the Giant. This is remarkable rather for its immense flow of water than for any peculiarity of structure. It has a rugged crater, shaped like the base of a broken horn, twelve feet high. Its cavity or nozzle is seven feet in diameter.