96 



EEPOET UNITED STATES GEOLOGICAL SURVEY. 



columns of steam shoot up tliroup;!! tlie water to tlie height of 300 feet. The ground 

 trembles, the vapor liisses through the vent with increased force. The water of the 

 crater is violently agitated, being thrown up in vast columns to the height of 30 and 

 40 feet, splashing out as far as the rim of the basin with great force. This continues 

 for half an hour, the water increasing in quantity in the crater all the while. Then 

 the steam ceases suddenly to escape, the water settles, and commences to lower in the 

 crater, continuing to fall to the depth of 35 feet, leaving bare the incrusted and fun- 

 nel-shai)ed walls, which converge at that depth to the diameter of 7 feet. The water 

 here stands for a time, the steam jets cease to hiss, the vapor vent to give forth its 

 fumes, and all is quiet. After the lapse of an hour, the water stoutly rises again, the 

 vents become active, and at the end of the regular period the whole performance is 

 repeated as before. 



1871. — We spent a couple of days at the Mud Yolcanoes in 1871 and 

 noted a numer of eruptions. In the report for 1871 I described the 

 eruption briefly as follows : 



Soon, however, there began a slight bubbling in the center, and the water began to 

 rise gradually in the basin until suddenly it was thrown into violent agitation, the 

 contents becoming very muddy. Immense volumes of steam escaped, throwing the 

 water to the heiglit of 20 feet. The eruption lasted about a quarter of an hour, when 

 it ceased as suddenly as it began, and the surface of the water was more placid than 

 before. This eruption took place eight times in twenty-six hours. 



After we left the locality, Mr. Carrington was sent back to observe 

 the geyser, and his report is found in Dr. Hayden's report. He says : 



We arrived at the mud geysers ten minutes after 9 o'clock a. m., July 1. [This 

 is a misprint ; it should be August 1.] The pool was calm, with exception of the little 

 boiling bubbles that are always on its surface. In circumference it measures nearly 

 100 feet. While selecting a place to camp, unsaddling our horses, &c., we heard a 

 loud, hissing noise, as an escape of steam. Hurrying to the geyser, I saw a wave 

 about three feet in height rise and die away to the left ; three similar ones followed 

 in quick succession. It then, ■with a dull, heavy sound, accompanied by dense col- 

 umns of steam, suddenly burst up to a height of 20 feet. It cootinued in action for 

 the space of fifteen minutes, when it ceased flowing as suddenly as it had commenced. 

 The average height of this flowing was about 15 feet, although some jets reached fully 

 30. Five minutes after the eruption, the pool measured 25 feet in circumference and 

 3 feet in depth, where before it was 100 feet in circumference and 11 feet in depth. 

 Ten minutes after (at 9.45 a. m. ), I noticed that it was slowly commencing to rise again. 

 It continued to do so until twenty minutes after one (1.20 p. m.), when it began to 

 boil near the center, a black formation making a ring around the boiling part. This 

 boiling gradually increased in violence, lasting twenty minutes; it then suddenly 

 stopped, and a wave 2 or 3 feet in height arose, dying away to the left, and the flow- 

 ing then took place as before described. Average height of this flowing, 15 feet ; 

 duration, 20 minutes. 



I tabulate the eruptions witnessed by Mr. Carrington, so that they 

 may be compared with those of 1872. 







ft 



S'S 



g.g 







o 



d 





^i 





























Date. 



pi 

 S 

 o 



o 



bo 



,0 fl 

 <0 O f^ 



r-. « . 



CS W 05 



t 





o 



+;,Q « 



"S S fl 



<y 





^ 



i-q 



S 



M 



w 



1871. 





M. 



H.M. 



H.M. 



Feet. 





1 



2 

 3 

 4 

 5 

 6 

 7 

 8 



15 

 20 

 15 

 20 

 15 

 15 

 15 

 10 











4 10 

 3 30 



3 30 



4 00 

 3 30 

 3 30 

 3 30 



3 55 

 3 10 

 3 15 

 3 40 

 3 15 

 3 15 

 3 15 









15 to 30 





2 





2 





2 , 









* This, in the original notes, is July, which is a misprint. 



1872. — In 1872 I spent about two days and a half at mud volcanoes, 

 and noted eight eruptions of the Mud Geyser, although they were not 



