112 



GEOLOGICAL SURVEY OF THE TEREITORIES. 



called the White Dome Geyser. (Fig. 42.) The broad mound is 15 feet 

 high, and upon this is a chimney about 20 feet in height. The steam 

 issues steadily from the top like a high-pressure engine. 



Early in the morning of August 30, the valley was literally filled with 

 columns of steam, ascending from more than a thousand vents. I can 

 compare the view to nothing but that of some manufacturing city like 

 Pittsburgh, as seen from a high point, except that instead of the black 

 coal smoke, there are here the white delicate clouds of steam. (Fig. 43.) 

 Small groups or solitary springs that are scattered everywhere in the 

 woods, upon the mountain-sides, and which would otherwise have 

 escaped observation, are detected by the columns of steam. It is evi- 

 dent that some of these groups of springs have changed their base of 

 operations within a comparatively recent period ; for aboutmidway on the 

 east side of the lower basin there is a large area covered with a thick, 

 apparently modern, deposit of the silica, as white as snow, while stand- 

 ing quite thickly all around are the dead pines, which appear to have 

 been destroyed by the excessive overflow of the water and the increased 

 deposition. These dry trees have a most desolate look ; many of them 

 have fallen down and are incrusted with the silica, while portions that 

 have fallen into the boiling springs have been reduced to a pulp. This 

 seems to be one of the conditions of siliciflcation, for when these pulpy 

 masses of wood are permitted to dry by the cessation of the springs, the 

 most perfect specimens of petrified wood are the result. In one instance 

 a green pine-tree had fallen so as to immerse its thick top in a large hot 

 basin, and leaves, twigs, and cones had become completely incrusted with 

 . . the white silica, and a por- 



^^' ^^' tion had entered into the cel- 



lular structure, so that when 

 removed from the water, and 

 dried in the sun, very fair 

 specimens were obtained. 

 Members of my party ob- 

 tained specimens of pine 

 cones that were sufficiently 

 silicified to be packed away 

 among the collections. 



In order that we might get 

 a complete view of the 

 Lower Geyser Basin, from 

 some high point, we made a, 

 trip to the summit of Twin 

 Buttes, on the west side of 

 the basin. From the top 

 of one of these buttes, which 

 is 630 feet above the Fire- 

 Hole Eiver, we obtained a bird's-eye view of the entire lower por- 

 tion of the valley, which was estimated to be about twenty miles long 

 and five miles wide. To the westward, among the mountains, were a 

 number of little lakes, which were covered with a huge species of water- 

 lily, Ntvphar advena. The little streams precipitated their waters in the 

 most picturesque cascades orfalls. One of them was named by Colonel 

 Barlow the Fairy Fall, from the graceful beauty with which the little 

 stream dropped down a clear descent of 250 feet. It is only from a high 

 point that it can be seen, for the water falls gently down from the lofty 

 overhanging clifl" into a basin at the foot, which is surrounded by a 

 line of tall pines 100 to 150 feet in height. The continual flow of the 



CATFISH GEYSER. 



