6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 66 
Fic. 6—White Dome Geyser, near Great Fountain, in eruption with hot 
waters cascading down its sides. This dome is in midst of broad plain, and 
owes its prominence to gradual deposit of siliceous matter largely by evapora- 
tion. Photograph by Walcott. 
Fic. 7—Ruins of Grotto Geyser, with two centers of eruption, Upper Geyser 
Basin. Photograph by Walcott. 
