PEALK.] HAYDEN'S valley SPEINGS — MUD VOLCANOES. 97 



consecutive as those of 1871 were. As my description of the eruption as 

 ■witnessed in 1872 contains some additional particulars to those already 

 given, I transcribe it from the report of 1872 (pp. 128-140). 



The following is the description of an eruption : The water gradually rises until the 

 inner basin is filled, when there is noticed a bubbling in the center. Suddenly, with- 

 out any further warning, it becomes violently agitated and an immense mass of 

 muddy water, mingled with clouds of steam, is thrown into the air. This action lasts 

 a few minutes and is followed by a lull, the action not ceasing entirely. Then it re- 

 commences with renewed violence, and the water fills the entire outer basin, the water 

 striking the banks in a succession of waves. The water is thrown up in a succession 

 of impiilsi's that follow each other rapidly, and sometimes the water is thrown ob- 

 liquely, aud seems as though it would overwhelm one standing on the bank. The 

 mass of water aud mud is immense. After the maximum height is obtained the jets 

 become smaller and smaller, and the eruption ends as suddenly as it began. It is a 

 very impressive sight, aud the stopping is like a calm after a storm. The water of 

 the geyser is very muddy, and bluish in color, having an acid reaction, due to the 

 presence of sulphuric acid. 



I will transcribe my field-notes below and then give the result in a tabulated form, 

 so that the whole may be placed before the eye at once. 



August 11. 



4.02 p. m. — The temperature of water in the basin is 140° F. and the air 50° F. 



4.37 p. m. — The water is rising rapidly and there is considerable bubbling in the 

 center of the basin, the temperature remaining the same. 



4.42 p. m. to 4.52 p. m. — The water is still rising and flows in currents, giving it a 

 variable temperature of 140° F. to 180° F. 



5.02 p. m. — The temperature is still 180° F. at the edge, although in the center it 

 must be considerably higher. It is still in ebullition. 



5.04 p. m. — The eruption commences. 



5.10 p. m. — There is a lull in the action. 



5.14 p. m. — The maximum (40 feet) is attained. 



5.17 p. m. — ^The eruption ends and the water at the edge of the basin has a temper- 

 ature of 172° F. 



5..52 p. m. — Temperature of water is 148° F. and the air 48° F. The water is 4 feet 

 lower than it was during the eruption, and the sides of the basin are shown sloping 

 inward. Several steam vents, not seen before, are now made apparent. The surface 

 of the water is quite placid, save in the center, where a slight bubbling takes place. 

 The water seems to be rising slowly. 



6.37 p. m. — The water has risen 1 foot since the last observation, and is still rising. 



7.37 p. m. — The water is now 6 inches above the level last observed. 



9.35 p. m. — The eruption commences. 



9.48 p. m. — The eruption ends. The maximum height was estimated at 20 feet, it 

 it being too dark to take any angles. 



August 12. 



6.19 a. m. — The geyser has evidently had an eruption during the night. The basin 

 is full and the center in ebullition. 



6.31 a. m. — The eruption commences. 



6.35 a. m. — There is a lull. 



6.42 a. m. — The eruption ends. The maximum height was 25 feet, and I noticed 

 that the ground shook beneath me while the eruption was going on. 



10.19 a. m. — The temperature of the water at the edge of the basin is 148° F. and 

 the air is 60° F. The center is bubbling, and a black, oily substance floats on the 

 surface. 



10.29 a. m. — The temperature of the water is from 140° F. to 180° F., and is rapidly 

 filling the basin. 



10.49 a. m. — The eruption commences. 



10. .55 a. m. — There is a lull. 



10..58 a. m.— The maximum (18 feet) is attained. 



11.02 a. m. — The eruption ends. 



11.08 a. m.— The temperature at the edge of the basin is 170° F.; air, 60° F. The 

 water has fallen a foot already. 



11.15 a. m.— Water, 1.50° F.; air, 60^ F. The water has fallen 18 inches. 



11.20 a. m. — The water has fallen 5 inches since the last measurement. 



11.24 a. m. to 11.29 a. m. — The water still has a temperature of 150° F., and has 

 fallen 2 feet 10 inches 



11.39 a. m. — The water has fallen 3 feet 2 inches since the eruption ceased (lowest 

 point). 



7 H, PT n 



