PEALE.] MA.MMOTH HOT SPRINGS OF GARDINEr's RIVER. 77 



a stair-case leading from the terrace. They are arranged in a compara- 

 tively narrow line near the lower end, and look somewhat like a line of 

 tubs piled one above the other. They extend down about 100 feet. 

 Below them the deposit is much broken, and consists of a mass of soft, 

 crumbling, white calcareous material. There are remnants of old basins, 

 among which dead trees are standing. Old basin ruins are seen also 

 toward the summit of the terrace. The deposits are white mingled with 

 red and yellow. On the east side of the mound on which are the springs 

 just described the basins are well marked, and extend down about 15 

 feet below the level of the springs. Fifty- five feet below is a projection 

 or table on which Spring JSTo. 16 is located. 



No. 16 is a greenish basin 5 feet by 12 feet, surrounded by red- stained 

 deposit. Where the water ov^erflows, green filaments like a confervoid 

 growth are seen in the channel. The temperature of the water in this 

 spring is 143° F. 



Ninth terrace of 1872. — This, at present, is really the main terrace 

 level, and is well shown in Plate V. It includes ten acres, and is about 

 280 feet above the level of the springs opposite the Cabin (Si)ring No. 1), 

 and about 200 feet above the camping place near Lookout Hill. On the 

 east and north sides the basins are prominent. The subterrace on which 

 Nos. 11 to 15 are is really a part of this terrace. On the northwest or 

 north side is a long ridge 3 to 5 feet high, which in 1871 had a fissure 

 in which the boiling water could be heard; and at its south or west end 

 was a spring with a temperature of about 162° F. This spring has dis- 

 appeared, although the fissure remains, and boiling can be heard far 

 beneath. On the south or southwest side of the terrace is another ridge- 

 like mass of deposit, 30 feet high, which is separated from the ter- 

 race level above by a hollow. Near the base of this ridge, a little above 

 the level of the terrace, is a mass of stalactic deposit, once the site of 

 a spring, which, from the curious shape, has been termed the Pulpit 

 (Plate III). In 1871 the fissure extending along this ridge was filled 

 with boiling water and steam, and sulphuretted hydrogen escaped from 

 it, as it did also in 1872. From Professor Comstock's account (page 208 

 of Jones's report) it was active in 1873, but this year (1878) it is almost 

 extinct; only at the northern end, in the hollow between the ridge of 

 next terrace, is there any sign of life, where there is a slight escape of 

 water from a small fissure (Spring No. 23). The temperature in this 

 spring is 165° F. This is really the site of the small geyser tubes that 

 in 1871 spouted intermittently to the height of 3 feet. In 1873 there 

 were three boiling springs here, but the geysers were not in action. 

 Now, however, we find only one spring, and a cone in which the spring 

 is extinct. The gully leading from this cone opens out onto the nmin 

 terrace. Returning to this we find two main groups of springs (17 to 

 20 and 21) on the central portion of the terrace, and another slightly 

 raised above its level. 



Ko. 17.— This is the principal spring of the first group. It measures 

 15 feet by 20 feet, and has a beautiful white, marble-like basin, in which 

 the transparent water has an exquisite light-blue tint. At a number ot 

 places on the surface are scum-like masses of lime carbonate floating 

 about like cakes of ice; some of them are red on the surface. The water 

 boils and bubbles constantly, a large portion of the ebullition being 

 probably due to the escape of carbonic acid gas and sulphuretted 

 hydrogen gas. The temperature is 105° F. The water from tlie spring 

 spreads out in minute terraces and shallow basins, extending toward 

 the group 11-15, and toward No. 21 particularly. Beneath the crust 



