184 GEOLOGICAL SUEYEY OF THE TERRITORIES. 



12 inclies across at tbeir bases. From the top of these the water emerged. 

 They were incrustecl with a caulitiower-like formatiou, and near them 

 iu a fissure we obtained balls of geyserite coated in the same manner. 

 The stream flowing from the lake is well tilled with a luxuriant growth 

 of Confervoidea. 



About a thousand yards farther south is the fourth group. The 

 raYine in which they are situated is about a mile and a half long and 

 three hundred yards wide. Of the many springs and geysers which it 

 contains, we took the temperature of forty-two, varying from 112^ F. to 

 198° F. The average temperature was 179^ F., the temperature of the 

 air being about 60° F. Just before entering the ravine we passed by a 

 large cone about 25 feet in height, from the top of which steam was 

 escaping. It is probabh' a geyser, although during our stay it did not 

 have an eruption. At the mouth of the ravine we found the principal 

 geyser of the group. Its basin was circular and about 60 feet in diame- 

 ter, although the spring itself, which is in the center, is only about 15 

 or 20 feet in diameter. The incrusted margin is full ot sinuses, tilled 

 with hot water, which falls into them whenever the geyser is in opera- 

 tion. These pockets contain, also, smooth, rounded pebbles of geyserite, 

 varying in size from that of a pea to a large-sized walnut. They have 

 been rouuded by the action of the water. The water in the spring of 

 the geyser was of a blue color and constantl^^ in agitation, though 

 more violently so just before spouting. The column of water i)rqjected 

 reaches the height of 100 feet, and is accompanied by imuiense clouds 

 of steam. Near the upper end of the ravine was a spring, about which 

 the deposit, instead of being white, was bhack. In some of the springs 

 we found butterflies which had fallen in and been scalded to death, and 

 on taking them out we found them coated with silica, thus commencing 

 to undergo petrifaction. 



About a thousand yards west of our camp, on the banks of the Fire- 

 Hole Kiver, was the fifth group, the largest of all, covering a space* of 

 nearly a square m.ile, and comprising a large number of springs and 

 geysers. We recorded the temperature of ninety-five, more than one- 

 half of Avhich were over 180o F. They varied from li2o F. to lOGo F., 

 the average being 172° F. ; the air at the time of observation was 70^ 

 F. One of the springs, from its resemblance to a shell, we named the 

 Conch Spring. One geyser resembled a fortress with numerous port- 

 holes, looking toward the river. Its temperature was 190^ F. In the 

 river were several small islands containing geysers. Opposite one of 

 them, on the edge of the river, was a horn-like geyser-cone, which we 

 named the Horn Geyser. Another we called the Cavern. There are 

 also a number of fumaroles, or vent-holes, from which steam coustautly 

 escai>es. ]S'ear the northern end of the groui) the river flows close to 

 the bas'e of a small wooded hiil, along the cdga of which were some 

 mud-springs and mud-geysers, the mud varying in color, being white 

 in some and blue in others. In some it was very thick, and in others 

 almost as thin as water. On ascending the hill alter Y)assing through 

 the woods, we came to a dozen or more interesting mud-springs. They 

 were almost all situated at the bottom of large fuimel-shaped craters, 

 of about 20 feet diameter at their mouths. The mud in most of them 

 was very thick and of a white or grayish color, and tlie steam in escap- 

 ing did so with a dull, thud-like noise, throwing back the mud in forms 

 resembling the leaves of a lily. Near these there were some small mud- 

 cones, from the top of which tbere was steam escaping. Breaking 

 them open, they were found to have veins of sulphur and iron running 

 through them. About two miles southwest of the last-mentioned group 



