■,* 



216 



GEYSERS OF ICELAND. 



[Ch. XXXIII. 



r 



and from 8 to 10 feet in diameter^ but gradually widening 

 as it rises into the basin. The inside of the basin is whitish 

 consisting of a siliceous crust, and perfectly smooth as are 

 likewise two small channels on the sides of the mound 

 down which the water escapes when the bowl is filled to the 



The circular basin is sometimes empty, as repre- 

 sented in the following sketch ; but is usually filled with 

 beautifully transparent water in a state of ebullition, 

 the rise of the boiling water in the pipe, especially when the 



margin. 



Durinir 



Fig. 129. 



View of tlie crater of the Great Geyser In Icelaiid. 



ebullition is most violent, and when tlie water is thrown up 

 in jets, subterranean noises are beard, like the distant firing* 

 of cannon, and the earth is slightly shaken. The sound then 



mor 



o^vn 



height of 100 or 200 feet. After playing for a time like an 

 artificial fountain, and giving off great clouds of vapour, 

 the pipe or tube is emptied ; and a column of steam, rushing 

 up with amazing force and a thundering noise, terminates 

 the eriiption. 



^ If stones are thrown into the crater, they are instantly 

 ejected ; and such is the explosive force, that very hard rocks 



sometime 



Henderson 



found that by throwing a great quantity of large stones into 



I 



I 



I 



C«' 



sS 



the f. 



er«P 



ti' 



as 



the 

 coin 



a 



roar 

 this 



ei 



lilt 



«?1T! 



See f 



b 



to 



tli 



( 



Perp 



ei 



^as|^ 



