750 



DYNAMICAL GEOLOGY. 



Iceland has long been noted for its geysers ; but it is far outstripped 

 by the region of the Yellowstone Park, explored and mapped by the 

 expeditions under the charge of Dr. F. V. Hayden. This locality is 

 situated about the head-waters of the Yellowstone and Madison, two 

 tributaries of the Missouri, and of the Snake River, a tributary of the 

 Columbia, at heights of 6,500 to 8,000 feet above the sea-level. The 

 geysers, which are mostly about the Fire-Hole Fork of the Madison, 

 and near Shoshone Lake at the head of Lake Fork of the Snake, are 

 exceedingly numerous, and play at all heights, up to 200 feet, or more ; 

 and, besides, there are multitudes of hot springs of various tempera- 

 tures, the most of them between 160° and 200° F., the boiling-point 

 of the region being 198° to 199° F. All together, the number of hot 



Figs. 1123-1125. 



1125 



Geyser-cones. — Fig. 1123, Giant Geyser ; 1124, Liberty Cap : 1125, Beehive Geyser. 



vents in this region cannot be less than 10,000. But the region is far 

 from fully explored ; and the geyser-areas east and southeast of Yel- 

 lowstone Lake, recently reported, may double this number. 



The hot waters of the Fire-hole Fork of the Madison and of the Shoshone Lake region 

 are siliceous, while those of Gardiner's River, a tributary of the Yellowstone, are 

 calcareous. Some of the fofms of the geyser-cones are shown in the accompanying 

 figures. Fig. 1123 represents the cone of the "Giant" Geyser, in the Upper Geyser 

 Basin of the Fire-hole; it is about ten feet high and twenty-four feet in diameter at 

 base, and has one side partly broken down and bent inward. It throws out, at long 

 intervals, a jet ninety to two hundred feet in height. The "Beehive" geyser-cone 

 (Fig. 1125), of the same region, is small, being but three feet high and five in diameter 

 at base; but its jet, shown in Fig. 1126, as it appears when in full play (from anexcel- 

 lent drawing by Mr. Holmes), is one of the highest, it exceeding two hundred feet. It 

 plays about once a day. Fig. 1124 represents the " Liberty Cap," one of the cal- 

 careous geyser-cones of the Gardiner River region, now extinct; it has a height of fifty 

 feet, and a diameter at base of twenty feet. "Old Faithful " is one of the largest of 

 the Madison River geysers ; it has a low and broad irregular cone, and throws up its 

 great jet to a height of one hundred and thirty feet, once in about sixty-five minutes, 

 the remarkable regularity of its action having suggested the name it bears. The 

 " Giantess " is another of the large geysers of the Fire-hole; the basin has a breadth 

 of twenty-three and a half by thirty-two and a half feet, and holds sixty-three feet in 

 depth of water, and at intervals throws the whole to a height of sixty feet. Another, 

 the "Architectural" geyser, is actually, when in action, a combination of jets of all 

 sizes and angles of inclination, each having some independence in its movements, but 

 all working together, and hence producing a marvellous effect from the ever-changing 

 views. 



Frank H. Bradley, of the expedition under F. V. Hayden, in 1872, observes that, 



