GEYSERS. 



103 



with perfectly transparent water, having a temperature of about 170° 

 to 180°. . 



Phenomena of an Eruption. — 1. Immediately preceding the erup- 

 tions sounds like cannonading are heard beneath, and bubbles rise and 

 break on the surface of the water. 2. A bulging of the surface is then 

 seen, and the water overflows the basin. 3. Immediately thereafter 

 the whole of the water in 

 the tube and basin is shot 

 upward one hundred feet 

 high, forming a fountain 

 of dazzling splendor. 4. 

 The eruption of water is 

 immediately followed by 

 the escape of steam with a 

 roaring noise. These last 

 two phenomena are repeat- 

 ed several times, so that 

 the fountain continues to 

 play for several minutes, 

 until the water is suffi- 

 ciently cooled, and then 

 all is again quiet until another eruption. The level of the water after 

 an eruption is seven or eight feet in the tube. The frequency of the 

 eruptions is slowly diminishing. In 180-i it was once every hour ; now 



Fig. 86.— (After Hayden.) 



Fig. 87.— The Turban (after Hayden). 



several days often elapse.* Throwing large stones into the tube has 

 the effect of bringing on the eruption more quickly. 



Yellowstone Geysers. — In magnificence of geyser displays, however, 

 Iceland is far surpassed by the geyser basin of Firehole River. This 



* Daubree, Archives des Sciences, vol. xix, p. 425, 1888. 



