72 hot springs; steam-jets. 



Geyser, and are not ended in so short a time. 

 They are repeated with great regularity, in some 

 springs in periods of a few minutes, in others of 

 several hours. The spring known by the name of 

 the Little Geyser may be instanced as one of 

 the most remarkable. The mouth of the Little 

 Geyser is in a conical mound of tufa, and is 

 partly covered with stones. Between these stones, 

 which at certain periods are left uncovered by the 

 water, the jet of boiling water forces its way from 

 time to time. The discharges, at the time of 

 Bunsen's visit, were repeated with great regularity 

 after periods of three hours and forty-five minutes ; 

 the chief outburst, which far surpassed all the 

 others in extent and beauty, taking place between 

 nine and ten o' clock in the morning. Its approach 

 makes itself known by a gradually increasing 

 escape of steam, and by a splashing of water under 

 ground. Then hot foam is thrown out with the 

 steam in jets, which rising and falling slowly at 

 intervals, keep mounting higher and higher, until 

 after about ten minutes, when the phenomenon has 

 reached its greatest development, they shoot up in 

 bundles, as it were, spirting upwards and sideways 

 to a height of thirty or forty feet. Then the jets 

 dwindle again in size and height, just as they 

 seemed to grow before, until, after another ten 

 minutes, the spring is again entirely at rest. 

 For the explanation of these periodical dis- 



