UPPER GEYSER BASIN OF FIREHOLE RIVER.

Just over the western margin of the Yellowstone Basin, yet within the limits of our great National Park, is the grand geyser region of Firehole River. Here, in a valley a dozen miles long and two or three wide, is an exhibition of boiling and spouting springs on a scale so stupendous that if all the corresponding phenomena of all the rest of the world could be brought into an equal area the display would seem as nothing in comparison.

Firehole River, the main fork of the Madison, has its source in Madison Lake, a beautiful sheet of water set like a gem among the mountains, dense forests of pines coming down to the very shores. A pointed ridge extends into the lake on the west side about half a mile, giving it the form of a heart. Its area is about three miles from north to south, and two from east to west. Its shores are paved with masses of trachyte and obsidian. The high mountains about the lake and along the river are gashed with deep gorges, with steep and jagged sides. Pines grow upon the mountain-sides where the declivity is so great that they cannot be scaled. In the obstructed gorges and on the mountain-tops, from 9,000 to 10,000 feet above the sea, little lakes occur every mile or so, nestled among the pines. Clear-watered mountain-torrents tumble down the almost vertical ridges to swell the Firehole, making cascades that in any other region would enjoy world-wide fame. Just before reaching the geyser-basin, some ten miles below the lake, the river roars through a deep gorge in the trachyte rock, and as it emerges, dashes over two cliffs, one twenty, the other fifty feet in height. "These pretty falls," writes Lieutenant Doane, "if located on an Eastern stream, would be celebrated in history and song; here, amid objects so grand as to strain conception and stagger belief, they were passed without a halt."

Shortly after, the caÑon widens and the dominion of the Fire King begins. Scattered along both banks of the river are boiling springs from two to twelve feet across, all in active eruption. The craters of these springs are from three to forty feet high. Like the springs on Gardiner's River, these gradually seal themselves up by depositing mineral matter around and over their orifices. Numbers of such self-extinguished craters, now cones of solid rock, are scattered along the river-side. Two miles further down the stream is the upper geyser-basin, an open, rolling valley, two miles wide and three long, the mountains on either side rising 1,500 feet above the valley, with steep, heavily-timbered ledges of dark rock.

Hurrying down the Firehole, thinking the wonders of the Yellowstone country had been left behind, and anxious only to reach the settlements of the Madison Valley, the expedition of 1871 was startled and astonished to see at no great distance an immense volume of clear, sparkling water projected into the air to the height of one hundred and twenty-five feet. "Geysers! geysers!" exclaimed one of the company, and, spurring their jaded horses, they were soon gathered around an unexpected phenomenon—a perfect geyser. The aperture through which the column of water was projected was an irregular oval, three feet by seven in diameter. The margin of sinter was curiously piled up, the exterior crust filled with little hollows full of water, in which were globules of sediment, gathered around bits of wood and other nuclei This geyser stands on a mound, thirty feet above the level of the surrounding plain, its crater rising five or six feet higher. It spouted at regular intervals nine times during the explorers' stay, the columns of boiling water being thrown from ninety to one hundred and twenty-five feet at each discharge, which lasted from fifteen to twenty minutes. They gave it the name of "Old Faithful."

"Near the crater, and as far as the irruptive waters reach," writes Lieutenant Doane, "the character of the deposit is very peculiar. Close around the opening are built up walls, eight feet in height, of spherical nodules, from six inches to three feet in diameter. These stony spheres, in turn, are covered with minute globules of stalagmite, incrusted with a thin glazing of silica. The rock, at a distance, appears the color of ashes of roses, but near at hand shows a metallic gray, with pink and yellow margins of the utmost delicacy. Being constantly wet, the colors are brilliant beyond description. Sloping gently from this rim of the crater in every direction the rocks are full of cavities in successive terraces, forming little pools, with margins of silica the color of silver, the cavities being of irregular shape, constantly full of hot water, and precipitating delicate, coral-like beads of a bright saffron. These cavities are also fringed with rock around the edges, in meshes as delicate as the finest lace. Diminutive yellow columns rise from their depths, capped with small tablets of rock, and resembling flowers growing in the water. Some of them are filled with oval pebbles of a brilliant white color, and others with a yellow frost-work which builds up gradually in solid stalagmites. Receding still farther from the crater, the cavities become gradually larger, and the water cooler, causing changes in the brilliant colorings, and also in the formations of the deposits. These become calcareous spar, of a white or slate color, and occasionally variegated. The water of the geyser is colorless, tasteless, and without odor. The deposits are apparently as delicate as the down on the butterfly's wing, both in texture and coloring, yet are firm and solid beneath the tread. Those who have seen the stage representations of "Aladdin's Cave," and the "Home of the Dragon Fly," as produced in a first-class theatre, can form an idea of the wonderful coloring, but not of the intricate frost-work, of this fairy-like, yet solid mound of rock, growing up amid clouds of steam and showers of boiling water. One instinctively touches the hot ledges with his hands, and sounds with a stick the depths of the cavities in the slope, in utter doubt in the evidence of his own eyes. The beauty of the scene takes away one's breath. It is overpowering, transcending the visions of the Moslem's Paradise."

As the next party of explorers were leaving the basin, ascending the river, this grand old geyser, which stands sentinel at the head of the valley, gave them a magnificent parting display. "With little or no preliminary warning," writes Dr. Hayden, "it shot up a column of water about six feet in diameter to the height of 100 to 150 feet, and by a succession of impulses seemed to hold it up steadily for the space of fifteen minutes, the great mass of water falling directly back into the basin, and flowing over the edges and down the sides in large streams. When the action ceases, the water recedes beyond sight, and nothing is heard but the occasional escape of steam until another exhibition occurs. This is one of the most accommodating geysers in the basin, and during our stay played once an hour quite regularly."

Old Faithful stands alone, though surrounded by a number of old geyser hills, whether built up in past ages by one spring shifting its position from time to time, or by a group of springs, now almost exhausted, it is impossible to tell.

Just across the river, and close to the margin, stands a silicious cone, very symmetrical, slightly corrugated on its exterior surface, three feet in height and five in diameter at its base. Its orifice is oval, with scalloped edges, and two feet by three in diameter. Of this unpretending cone Mr. Langford writes:

"Not one of our company supposed that it was a geyser; and among so many wonders it had almost escaped notice. While we were at breakfast upon the morning of our departure a column of water, entirely filling the crater, shot from it, which, by accurate triangular measurement, we found to be 219 feet in height. The stream did not deflect more than four or five degrees from a vertical line, and the eruption lasted eighteen minutes. We named it 'The Bee-hive.'"

A hundred yards further from the river, near the centre of the large group of spouting and boiling geysers, of which the Bee-hive is one, is a large oval aperture with scalloped edges, the diameters of which were eighteen and twenty-five feet, the sides corrugated and covered with a greyish-white silicious deposit, which was distinctly visible at the depth of one hundred feet below the surface.

"No water could be discovered," writes Mr. Langford, on his first approach to the spring, "but we could distinctly hear it gurgling and boiling at a great distance below. Suddenly it began to rise, boiling and spluttering, and sending out huge masses of steam, causing a general stampede of our company, driving us some distance from our point of observation. When within about forty feet of the surface it became stationary, and we returned to look down upon it. It was foaming and surging at a terrible rate, occasionally emitting small jets of hot water nearly to the mouth of the orifice. All at once it seemed seized with a fearful spasm, and rose with incredible rapidity, hardly affording us time to flee to a safe distance, when it burst from the orifice with terrific momentum, rising in a column the full size of this immense aperture to the height of sixty feet; and through and out of the apex of this vast aqueous mass, five or six lesser jets or round columns of water, varying in size from six to fifteen inches in diameter, were projected to the marvellous height of two hundred and fifty feet. These lesser jets, so much higher than the main column, and shooting through it, doubtless proceed from auxiliary pipes leading into the principal orifice near the bottom, where the explosive force is greater.... This grand eruption continued for twenty minutes, and was the most magnificent sight we ever witnessed. We were standing on the side of the geyser nearest the sun, the gleams of which filled the sparkling column of water and spray with myriads of rainbows, whose arches were constantly changing,—dipping and fluttering hither and thither and disappearing only to be succeeded by others, again and again, amid the aqueous column, while the minute globules into which the spent jets were diffused when falling sparkled like a shower of diamonds, and around every shadow which the denser clouds of vapor, interrupting the sun's rays, cast upon the column, could be seen a luminous circle radiant with all the colors of the prism, and resembling the halo of glory represented in paintings as encircling the head of Divinity. All that we had previously witnessed seemed tame in comparison with the perfect grandeur and beauty of this display. Two of these wonderful eruptions occurred during the twenty-two hours we remained in the valley. This geyser we named 'The Giantess.'"

The central spring of this group stands on the summit of a great mound built up in thin layers, by the continual but moderate overflow of the spring. The crater is twenty feet in diameter, slightly bubbling or boiling near the centre, and with a thin, elegant ring projecting a few inches over the water. Looking down into the clear water of this spring one seems to be gazing into fathomless depths, while the bright blue of the water is unequalled even by the sea. There are many such central springs, usually crowning the summits of mounds, and with projecting rims carved with an intricate delicacy truly marvellous, and adorned with colors that defy description. "The great beauty of the prismatic colors," writes Dr. Hayden, "depends much on the sunlight; about the middle of the day, when the bright rays descend nearly vertically, and a slight breeze just makes a ripple on the surface, the colors exceed comparison; when the surface is calm there is one vast chaos of colors, dancing, as it were, like the colors of a kaleidoscope. As seen through this marvellous play of colors, the decorations on the sides of the basin are lighted up with a wild, weird beauty, which wafts one at once into the land of enchantment; all the brilliant feats of fairies and genii in the Arabian Nights' Entertainments are forgotten in the actual presence of such marvellous beauty; life becomes a privilege and a blessing after one has seen and thoroughly felt its cunning skill."

Across the river, and a short distance below this group, is the largest and most imposing formation in the valley—the crater of Castle Geyser. This geyser receives its name from its resemblance to the ruins of an old castle as one enters the valley from the east. The deposited silica has crystallized in immense globular masses, like cauliflowers or spongiform corals, apparently formed about a nucleus at right angles to the centre. The entire mound is about forty feet high, and the chimney twenty feet. The lower portion rises in steps formed of thin laminÆ of silica, mostly very thin, but sometimes compact, an inch or two thick. On the southeast side, where the water is thrown out continually, these steps are ornamented with the usual bead and shell work, with the large cauliflower-like masses: but the other portions are fast going to decay, and the dÉbris are abundant. This has undoubtedly been one of the most active and powerful geysers in the basin; it still keeps up a great roaring inside, and every few moments, as observed by Dr. Hayden, it throws out a column of water to the height of ten or fifteen feet. Occasionally it seems to have more imposing eruptions, since on one occasion Lieutenant Doane saw it throw a column of water to the height of sixty feet, with the escape of heavy volumes of steam. The next year Colonel Barlow saw a similar display. According to the latter observer, the base of the crater is three hundred and twenty-five feet in circumference, and the turret one hundred and twenty-five. At the base of the turret lies a large petrified pine log, covered with a brilliant incrustation several inches thick.

Across the river, and a little below the Castle, are some fifty springs and geysers, the chief of which has been called Grand Geyser, its power seeming greater than that of any other in the valley. Lieutenant Doane describes this magnificent geyser as follows:

"Opposite camp, on the other side of the river, is a high ledge of stalagmite, sloping from the base of the mountain down to the river. Numerous small knolls are scattered over its surface; the craters of boiling springs from 15 to 25 feet in diameter; some of these throw water to the height of three and four feet. On the summit of this bank of rock is the grand geyser of the world, a well in the strata, 20 by 25 feet in diametric measurements, (the perceptible elevation of the rim being but a few inches,) and when quiet having a visible depth of 100 feet. The edge of the basin is bounded by a heavy fringe of rock, and stalagmite in solid layers is deposited by the overflowing waters. When an eruption is about to occur the basin gradually fills with boiling water to within a few feet of the surface, then suddenly, with heavy concussions, immense clouds of steam rise to the height of 500 feet, and the whole great body of water, 20 by 25 feet, ascends in one gigantic column to the height of 90 feet; from the apex of this column five great jets shoot up, radiating slightly from each other, to the unparalleled altitude of 250 feet from the ground. The earth trembles under the descending deluge from this vast fountain; a thousand hissing sounds are heard in the air; rainbows encircle the summits of the jets with a halo of celestial glory. The falling water plows up and bears away the shelly strata, and a seething flood pours down the slope and into the river. It is the grandest, the most majestic, and most terrible fountain in the world. After playing thus for twenty minutes it gradually subsides, the water lowers into the crater out of sight, the steam ceases to escape, and all is quiet. This grand geyser played three times in the afternoon, but appears to be irregular in its periods, as we did not see it in eruption again while in the valley. Its waters are of a deep ultramarine color, clear and beautiful. The waving to and fro of the gigantic fountain, in a bright sunlight, when its jets are at their highest, affords a spectacle of wonder of which any description can give but a feeble idea. Our whole party were wild with enthusiasm; many declared it was 300 feet in height; but I have kept, in the figures as set down above, within the limits of absolute certainty."

ill144

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.

ill153

During its quiescent state the boiling water can be seen in its chambers at a depth of forty feet, the action of the steam and water together producing a loud, rumbling sound. Near, and acting in concert with it, are half a dozen smaller craters from two to eight feet in height, constantly full of water, and boiling violently from two to six feet into the air. "This great geyser," says Lieutenant Doane, "played several times while we were in the valley, on one occasion throwing constantly for over three hours a stream of water seven feet in diameter, from 90 to 200 feet perpendicularly. While playing it doubled the size of the Firehole River."

At the base of the mountain further south is a remarkable geyser, discovered by Colonel Barlow, and called by him the Comet.

The crater of this geyser is very beautiful, though, being but slightly elevated above the general slope of the plateau, it might easily be overlooked, should it not happen to play during the visit of an examining party. There are three openings. One, a very small aperture, emits puffs of steam, similar to the exhaust-pipe of a steam engine. The large one in the centre, six feet across, boils violently during an eruption, but does not throw water to a great height. The third opening is the geyser proper. It is twelve by eighteen inches in diameter, somewhat narrowed as it descends, and is of great depth—smooth and straight. These cavities are all lined with delicate deposit, beautifully enamelled, in appearance as delicate as frost-work, but hard and strong, requiring the assistance of a hammer to detach fragments for specimens. Soon after Colonel Barlow entered the basin he witnessed a grand eruption of this geyser. He says:

"A roar was heard near the hill-side a hundred yards distant, and upon rushing out in that direction we saw a huge mass of steam issuing from a crater at the base of the hill, accompanied by a column of water rising to a height far exceeding that of any geyser yet seen. This grand fountain continued to play for several minutes, when, having subsided, I approached to obtain a closer view of the aperture whence had issued such a powerful stream. A sudden gush of steam drove me away, following which the water was again impelled upward and upward, far above the steam, until it seemed to have lost the controlling force of gravity. The roar was like the sound of a tornado, but there was no apparent effort—a steady stream, very graceful and perfectly vertical, except as a slight breeze may have waved it to and fro. Strong and smooth, it continued to ascend, like the stream from a powerful steam fire-engine. We were all lost in astonishment at the sudden and marvellous spectacle. I have no hesitancy in stating that this geyser played to the height of over two hundred feet. It commenced at five o'clock in the afternoon and continued twenty minutes.

"The enthusiasm of the party as they watched this wondrous display knew no bounds. Those who were usually loud and boisterous in the exhibition of their feelings, became subdued and simply gazed in silent awe; while the more sober members seemed to lose their natural gravity and manifested their delight in shouts of rapture. For myself, I remember trying to obtain a view of the fountain from all points of the compass at once, and was brought to a realizing sense of the difficulties attending the execution of this desire, by discovering that I was waiting in the torrent of hot water which was now flooding the nearly level surface of the surrounding rock.

"After the grand column of water subsided, vast clouds of steam, were for some time ejected from the throat of the geyser, and also from a small rent close beside the main orifice.

"During the following day we watched this crater with increasing vigilance in the hope of witnessing another of its stupendous exhibitions. The photographer kept his camera levelled upon the spot all day, and careful arrangements for triangulating the height of the column were also made. But though numerous indications of another eruption were observed at intervals by the rising of the water with violent ebullitions, no explosion occurred till about ten o'clock at night, when the grand performance was repeated. The spectacle by moonlight was truly sublime, but less satisfactory than in the day, since it was more difficult to distinguish between the column of water and the masses of vapor escaping with it. The interval between its eruptions was approximately determined as about twenty-nine hours; we therefore reasoned that it would play again at three o'clock the following night, and at eight on the succeeding morning. But we were doomed to disappointment; the eruption persisted in taking-place before daylight on the three succeeding nights, thus preventing the observations we so much desired to make."

Two hundred yards below the Giant is the Grotto so named from the curious irregularity of its inclosing walls. It has an exceedingly intricate formation, with fantastic arches, pillars, and turreted sides, and discharges several times a day. Several of the first explorers crawled through the sinuous apertures when all was quiet. It seemed as harmless as curious then, but their opinion was changed slightly when they saw it an hour after throwing a column of water six feet in diameter to the height of sixty feet. Near it are several vents in which the water boils constantly to the height of six feet, large streams running down the banks into the river.

Around the point of a hill a few hundred yards south of the Grotto, and partially concealed by a grove of pines, is a white cone twenty-five feet high and a hundred feet in diameter at the base. It has evidently been a geyser of considerable importance, but it now merely sends forth puffs of steam from a small orifice at the top. Near it is a quiet hot-spring with a most elegantly scalloped rim. Back of this Pyramid is the Punch Bowl, and still further south, the Black Sand Geyser, neither of which has been specially described.

Returning to the river and crossing we find at the water's edge, nearly opposite the Grotto, the Riverside Geyser, and a short distance below, on the same side, is the Fan. The latter geyser has a double orifice, which discharges five radiating jets to the height of sixty feet, the falling drops and spray giving the appearance of a feather fan. The effect is very beautiful. Its eruptions are frequent, lasting usually from ten to thirty minutes. A vent connected with it, about forty feet distant, expels dense masses of vapor fifty or sixty feet high, accompanied by loud, sharp reports, during the time the geyser is in action. Lieutenant Doane describes the curious action of these vents as follows:

"First the steam would rush from the upper crater, roaring violently, then this would suddenly cease, to be followed by a fan-like jet of water rising from the lower crater to the height of over forty feet, playing for perhaps two minutes; then this would suddenly stop flowing, and the steam would rush forth again for a time. Occasionally the small crater threw a transverse stream, alternating with the others; and thus they played on for hours, after which all would subside to a gentle bubbling."

ill158

Along both banks of the river are small craters built up in every conceivable shape. Several streams pour out cascades from round holes in the rocky bank of the river, and all around are little geysers playing at intervals from six to forty feet.

A plateau opposite the Fan contains fifteen hot springs of various characteristics; some are of a deep blue color and have fantastic caverns distinctly visible below the surface of the water. The openings at the surface are often beautifully edged with delicately wrought rock fringes. One variety deposits a red or brown leathery substance, partially adhering to the sides and bottom of the cavern and waving to and fro like water plants. In size these springs vary from five to forty feet in diameter.

Two hundred yards below the Fan are two lively geysers called the Sentinels. The one on the right bank of the stream is in constant agitation, its waters revolving horizontally with great violence, occasionally spouting upward to the height of twenty feet, with a lateral projection of fifty feet. Much steam is thrown off at each eruption. The crater of this geyser is three feet by ten. The companion Sentinel on the other side of the stream is smaller and less active. At this point the river-valley is narrow and the stream rapid, with a considerable fall. Forty or fifty comparatively unimportant geysers and boiling springs are scattered along the narrow valley to the junction of Iron Spring Creek, the lower limit of the Upper Geyser Basin.

Iron Spring Creek, a stream about half the size of Firehole River, takes its name from a group of springs on its banks, about a mile south of the Giant. Among the most noticeable of these is a group of eight beautiful springs enclosed in a single rim, one hundred and forty feet in length. The interior of the basin is lined with a rose-colored deposit. These springs are situated on the crest of an eminence incrusted with rocky deposits which encroach on the adjacent forest, whose dead and whitened trunks bear evidence of the deadly effect of the hot water flowing among them. On a considerable mound, at the junction of Iron Creek with the main stream, is a group of geysers that do not differ materially from those already described. The central member of the group is known as Soda Geyser.

ill161