PEALE.] THIED GEYSER BASIN OF FIRE HOLE RIVER. 249 



witli a fine profile of a mild-featnred human face done in the head-work. The top of 

 the mound is perforated with numerous small three, four, and five angled apertures, and 

 a single larger one hetweeu 2 and 3 inches in diameter. In eruption this larger open- 

 ing throws a stream from 20 to 50, and even to 70 feet in height, mostly in drops with 

 much steam. Though the amount of water ejected is small, yet the force is very 

 great, and, in this respect, the eruptions much reminded us of those of the Castle 

 Geyser. Its highest jets are generally ahout the midde of the period of eruption. 

 Eruptions take place at somewhat irregular intervals, hut generally are ahout two 

 hours apart. During such as were carefully ohserved, there was first a period of vio- 

 lent activity, continuing from 3 to 4 minutes and ceasing suddenly ; then a quiet in- 

 terval of from 11 to 24 minutes : then a second active period of from 23 to 26 minutes, 

 closing gradually with a rush of steam and occasional water-jets. The small vents' 

 spit furiously all through the eruption, their jets reaching 3 feet or more in height, 

 when the main jet was at its culmination. About 10 yards off, on the platform, a small 

 vent is in sympathy, hut it is so nearly stopped as to he generally overlooked. I think 

 it probable that this was wider in the younger days of the geyser, and has become 

 stopped up equally with the latter. It is evident that eruption at this point must soon 

 cease, unless the great force developed beneath shall be able to break away the upper 

 part of the dome. It is more probable, however, from facta observed in the other 

 basins, that a new vent will be opened and a new mound built. I could not obtain 

 the temperature of the water of the geyser, since the water, except just before and. 

 during the eruption, re tired below the surface-openings, and we had no self-registering 

 thermometers with which to measure its heat from a safe distance. The surrounding 

 springs, which are nearly all boiling, gave temperatures varying from 185° to 192°. 

 The general elevation of the basin is about 7,770 feet, at which the theoretical boiling 

 point is about 198°. The single geyser of the basin was called the Solitary. 



This small basin spreads perhaps a half mile from the stream, and includes near its 

 northwest comer another cluster of hot springs, some of which reach 186°, surrounded 

 by variously colored deposits, including some sulphur. The trail of our main party 

 entered the basin at this point. The central part of the basin shows the vents and 

 deposits of numerous scattered springs, most of which are nearly or quite extinct, 

 only a few of them still boiling.* 



After a short interval of timber, another, small meadow-like basin opens to view, oc- 

 cupied by a few small warm springs of no importance. 



The basin surrounding the head or the river is occupied by quite a large meadow, 

 tolerably dry in the middle, where the stream winds along, but very swampy all 

 arouijd its border, where numerous cold springs escape from tbe hills. The sites' of a 

 few old hot springs, long since extinct, are marked by the patches of the much-disin- 

 tegrated white geyserite, now mostly buried under the tall grasses and sedges which 

 cover the meadow. t 



It will be seen from the descriptions just quoted that the springs of 

 the Third Geyser Basin are in a dying condition as compared with those 

 of the Lower and Upper Basins. 



Section III.— SPEIN^GS OK SKAKE EIVER DEAINAGE. 

 CHAPTER X. 



SHOSHONE GEYSER BASIN. 



The Shoshone Geyser Basin is located at the western end of the west- 

 ern arm of Shoshone Lake, and comprises an area of about a square 

 mile. At present the active springs are scattered along both banks of 

 Shoshone Creek for a distance of more than half a mile. Most of the 

 springs are separated from the lake by low timbered hills. 



History. — The Shoshone Geyser Basin was named by Professor Brad- 

 ley in 1872, from Shoshone Lake, although properly the lake should 

 probably be known as De Lacy's Lake, but, as in the case of Yellow- 

 stone Lake, the name that has the right of priority has not been retained. 

 We passed around a part of tlie lake in 1871, but supposed it was the 

 head of the Madison, aud it was so named on our map of that year. 



t Report of U. S. Geol. Survey for 1872, 1873, pp. 241,242. tlfcid., p. 234. 



