220 



EEPORT UNITED STATES GEOLOGICAL SUEVEY. 



■wliicli probably mark the sites of extinct geysers, their deposits being 

 broken and shelly, evidently disintegrating. From one of them steam 

 escapes occasionally, but the orifice is so choked with broken geyserite 

 that I was unable to take the temperature of the water in it. This cone 

 is one of the favorite points from which to view the eruptions of Old 

 Faithful. There are several small vents on the mound of the geyser, 

 which appear to mark the line of a fissure of the orifice of which the 

 geyser is a part. It is probable that Old Faithful is the most recent of 

 the cones, or mounds, which mark this location, and that when it broke 

 forth the other cones ceased their geyseric action. The springs of the 

 group are near the river, on a high mound, which, however, is lower 

 than the level of the geyser. They have high temperatures. The fol- 

 lowing table presents all the data in reference to them : 



Talle of Old Faithful Group. 



"No. and 

 name. 



Size and depth. 



O; CD 

 -i3 IB 



•-2 ^ 

 ^ S 



m 



Deep temperatures. 



i 



03 



u 



o 



Eemarks. 



Old Faithful 



Orifice is 2 by 6 feet. 



*199 

 1200 

 +170 





5.30 p.m.. 

 5. 50 to 5.58. 



.... 





geyser. 

 1 





temperature, see 

 text following 

 table. 



Choked with deposit. 



Greenish-hued pool. 



Boiling spring, with 

 inky-hued water 

 in a white basin, 

 with white border. 



Black boiling spring. 





2 



U by 9 feet ; 7 feet 

 10 inches deep. 



4 by 5§ feet ; 15 J feet 

 deep. 



3 by 3 feet 3 inches ; 



16 feet deep. 

 9 by 16 inches... 



197 

 196 



198 

 185 



6i feet below the 

 surface, 200°. 



14 feet below the 

 surface, 199°. 



14 feet belo-w the 

 surface, 207°. 









3 







4 







5 















geyser. 



* steam 4 or 5 feet in crater. 



1 Spurts of steam. 



i Pools outside. 



DESCRIPTION. 



Old Faithful Geyser (Plate XXII). — This geyser was named by Mr. 

 N. P. Langford, and well sustains the reputation given it by the Doane 

 and Washburn expedition of 1870. It has been called the Guardian of 

 the Valley. It is so regular in its operations and they occur so frequently 

 that it has afforded unusual facilities for observation. It is a mound 

 or table of geyserite, measuring at the base 145 by 215 feet, and at the 

 top 20 by 54 feet. It rises 11 feet 11 inches above the surrounding level, 

 and is composed of layers of deposit arranged in a succession of small 

 steps that nre made up of small basins. IsTear the top these basins are 

 beautiful, broad, shallow pools, with pink, cream, white, brown, and gray 

 bottoms, in which the water after the eruptions stands and is of a deep- 

 azure tint. 



The chimney, or crater, of the geyser has an oblong opening measuring 

 4 by 8 feet on the outside and 2 by G feet inside. This slopes inward, and 

 is the top of a basin about 5 feet deep, at the bottom of which is an irregu- 

 lar orifice, the head of the geyser tube. The inside of the basin is of a 

 dark-yellow and rusty color. There is little doubt that this orifice marks 

 the situation of a former fissure, and this part has been formed into a 

 basin by the deposition of geyserite on its sides, which has acted as a 

 perfect cement. This fissure was probably in geyserite, at the surface 

 at least, and was caused perhaps by some obstruction in some of the 



