PEALE.] HAYDEN's valley springs MUD VOLCANOES. 99 



reached a height of 20 to 30 feet. On his first visit he found the water 

 receding, and was obliged to leave before the eruiDtion took place. * 



1875. — Captain Ludlow in his report describes the eruption of the gey- 

 ser in 1875 :t 



About 4 p. m. pistol sliots from the Mud Geyser summoned us to witness an explo- 

 sion. The water had risen gradually until the smaller springs Avere submerged and 

 the basin enlarged to its full dimensions. Near the center, the geyser was boiling 

 and bubbling actively, and soon spurted to a height of 5 or 6 feet, failing and rising 

 again, and alter about three minutes of excitement subsided, the water lowered, being 

 gradually swallowed down the several oriLices, aaid the discharge was over. The 

 geyser has a period of about 4^ hours, and several of the subsequent eruptions were 

 witnessed. None exceeded 10 or 15 feet. 



1876 and 1877. — lean find no record of any observations for 1876, but 

 i in 1877 General Sherman's party visited this locality and saw the geyser 

 I in action. Col. O. M. Poe, of his party, says: 



t It has an interval of somewhat more than an hour, and rises above the ordinary 



i level to a height of 5 or 6 feet, with considerable disturbance. 

 1878. — We arrived at the Mud Springs or volcanoes on the afternoon 

 ■ of the 26th of September, and left on the morning of the 29th, and during 

 this time the basin of the Mud Geyser whenever seen was full of water, 

 so that the inner hard basin or bowl was not seen. The water also 

 ', covered springs 2 and 3, which in 1872 were seen to be independent. A 

 ; great many points of ebullition were noticed over the crater of the 

 t geyser, and the steam vent alongside of the geyser in the bank con- 

 '. tained water through which the steam escaped with a thumping sound. 

 On September 27 I saw an eruption which began at 9.29 a. m. ^t 

 consisted only of a bulging of the mass of water, which attained a height 

 ' of perhaps 3 feet in a surging, splashing mass, muddying the pool sur- 

 ; rounding. The water in the latter was thrown into waves. This erup- 

 ; tion ended in 1 minute and 15 seconds, and the water did not recede as 

 in the eruptions seen in 1871 and 1872. The temperature in the basin 

 was 127° F., but this temperature was on the edge, as it was impossible 

 to reach to the central orifice. 



It is difficult, in view of the limited data we have, to determine 

 whether this geyser is declining in activity or not. Just before our 

 visit there had been a great deal of snow and rain, which probably had 

 'something to do with the tilling of the basin, and may have diminished 

 the apparent activity. We really know nothing of the ettects of the 

 variations in the supply of water uj^on the geysers and hot springs. 

 There is no doubt, however, that the greater the body of water snpi)lied by 

 rain and snow the lower is the surface temperature. Those taken this 

 year were much lower than the ones taken in 1871 and 1872. In the tem- 

 perature of those years a decrease of 11° was noted from 1871 to 1872. 

 It seems probable therefore that there has been some actual decrease 

 in the activity of the Mud Geyser. Lieutenant Doane speaks of the 

 action lasting half an hour in 1870. In 1871, as we have seen, the dura- 

 tion was about 15 minutes, which in 1872 had decreased to 12 minutes, 

 and in 1875, according to Captain Ludlow, it was only about 3 minutes. 

 In 1878 the eruption I witnessed was only 1 minute and 15 seconds in 

 length. It is possible of course that there is an irregular regularity 

 which will haA'e to be determined by future observations. The height 

 to which the geyser spouts also a]){)ears to be diminishing. In 1870 

 it was 30 feet or -JO feet; in 1871, 15 feet to 30 feet; in 1872, 18 feet to 

 40 feet; in 1875, 5 feet to 15 feet; and in 1878 only about 3 feet at the 

 one time noted. 



* The Great Divide, p. 237. 



t Report of Reconnaissance from Carroll Mountains to Yellowstone Park, 1875, p. 24. 



