310 



EEPORT UNITED STATES GEOLOGICAL SUKVEY. 



stant ebullition, except just before an eruption, wMcb begins witliout 

 any other premonitory symptoms or detonations, as in the case of the 

 Great Geyser. The jets during the eruptions are lanceolate, and follow 

 each other rapidly. Eruptions can be brought on by stopping up the 

 tube with clods of earth and stones. This stopping of the tube hinders 

 the disengagement of the steam and increases the pressure, which at 

 last suddenly removes the impediment. 



The following is a description of an eruption by Henderson, who saw 

 it in action in 1814 : 



It is scarcely possible, however, to give any idea of the brilliancy and grandeur of 

 the scene which caught my eye on drawing aside the curtain of my tent. * ^ * 

 A column of water, accompanied with prodigious volumes of steam, was erupted with 

 inconceivable force and a tremendously roaring noise to varied heights of from 50 to 

 80 feet, and threatened to darken the horizon, though brightly illumined by the morn- 

 ing sun. * * * At length I repaired to the fountain, where we all met and com- 

 municated to each other our mtitual and enraptured feelings of wonder and admira- 

 tion. The jets of water now subsided, but their place was occupied by the spray and 

 steam, which, having free room to play, rushed with a deafening roar to a height little 

 inferior to that of the water. * * * After continuing to roar about half an hour 

 longer the column of spray visibly diminished and sank gradually till twenty-six 

 minutes past six (it began at twenty-three minutes past five), when it fell to the same 

 slate in which we had observed it the preceding day, the water boiling at the depth 

 of about 20 feet below the orifice of the shaft. 



From this descriiDtion it is evident that Strokhr has a steam period of 

 considerable length, in which it is very much like a number of the gey- 

 sers in the Yellowstone National Park. 



In the following table are compiled the observations of different ob- 

 servers. So much time has always been devoted to the examination of 

 the Great Geyser that Strokhr has often been neglected. 



TaMe of observations on Strokhr Geyser. 



ii 



Observer. 



Size of tube. 





Interval or period. 



Duration of erup- 





Diameter. 



Depth. 



tion. 



1789 



Sir John Stanley 



6 feet 10 

 inches. 



Feet. 



Feet. 

 132 



60 



70 

 50 to 80 



120 



92 



160 



162 



90-100 







1809 



Sir J. W. Hooker 



Every 10 or 12 

 hours. 





1810 









Half hour. 



1814-15 



Ebenezer Henderson 



Dillon 



9 feet 



44 





Water period 

 over 15 minutes; 

 "whole eruption 

 1 to 1 hour. 



1834-'35 





1836 



French expedition 



Bunsen 



8 feet 



7 feet 



65 

 43 



42 

 87J 



57 







1846 







1846 









1855 



Eobort Allen 



Under 9 



feet. 

 9 feet 







1855 



Kohert Chambers 







1856 



Lord Duiferin 



40 







]861 



Eev. Fred. Metcalf 



C.W. Paijkull 



6 feet 



48 







1865 







Lasted 2 hours. 



1867 









60 or 70 

 120 







1874 













1881 





10 feet.... 



42 

















Little Geyser and Roarer. — The Little Geyser spouts only, from 10 to 

 20 feet about every two hours. Its basin or bowl is about 12 feet in 

 diameter, and very handsomely ornamented. The pipe leading down- 

 ward from the basin is very irregular, having a dejJth of 38 feet and 

 diameter of 3 feet. 



