258 



EEPOKT UNITED STATES GEOLOGICAL SURVEY. 



5.55 p. in.,the water in the center cone is within afoot and a half of 

 the top, and the surface temperature is 198° F., 5^ feet below it is 207° F. 



Au(just2^. — During the night the geyser has been making a great deal 

 of noise, and the north cone and the vent between center and south 

 cones have been overflowing. 



August 25. — At 8 a. m. the center cone spouts over the edge at inter- 

 vals, the water is within a foot of the top, and has a surface tempera- 

 ture of 199°, and 6 feet below 207°. 



August 26. — An eruption of the geyser was exjiected this evening, but 

 has not taken place. 



August 27. — We left the Shoshone Basin about 9 a. m., and up to 

 that time no eruption had taken place, although the water is in violent 

 agitation and kept so throughout the night. 



The following is the description of the eruption of the Union Geyser 

 given by Professor Bradley in 1872 : * 



During eruptions the west (south) vent spouts a little water 2 or 3 feet high, for 

 from 1 to 2 minutes, and then yields a moderate flow of steam. Meanwhile the center 

 vent is throwing a very powerful jet from 70 to 90 feet into the air, which, after 

 about 5 minutes, gradually gives place to steam, the mingled steam and water giving 

 the highest jets. The east (north) vent, spouting from 10 to 50 feet, throws a solid 

 hoby of water for about 10 minutes, when the whole supply of water seems to be ex- 

 hausted, and the rush of steam from all the vents becomes more violent and continues 

 some 40 or 50 minutes longer, gradually declining, however, though with many spas- 

 modic renewals. A small, flat opening in the space between the central and western 

 (southern) vents gives exit to a little water while the geyser is preparing for eruption, 

 but takes no part in the eruption itself. 



This description of the eruptions in 1872 answers very well for those 

 noted in 1878. 



The following table gives the eruptions witnessed by Professor Brad- 

 ley in 1872 : 



No. 



Eruption be- 

 gan. 



Length of water eruption. 



Total length. 



Height. 



Interval be- 

 tween be- 

 ginnings. 



1 



h. m. s. 

 10 28 00 a. ni. 



1 55 GO p. m. 

 10 25 00 p m. 



5 minutes in the central 

 cone, 10 minutes in east 

 (north) cone. 



47 minutes 



56 minutes... 



70 to 92 feet from the 

 central cone, 10 to 

 50 feet fiom east 

 (north) cone. 



70 feet 



h. m. s. 

 3 27 00 



3 





8 30 00 













The following table notes the eruptions of 1878 seen by us: 



^0. 



Date- 



Eruption be- 

 gan. 



Length of the water 

 eruption. 



Total 

 length. 



Height. 



Intervtil be- 

 tween be- 

 ginnings. 



1 



Aug. 15, 1878 



Aug. 15, 1878 

 Aug. 10, 1878 

 Aug. 21, 1878 



Aug. 21, 1878 



h. m. s. 



6 45 00 p. m. 



9 35 00 p. m . . 

 3 40 00 it. m . . 



7 46 00 a. m . . 



10 37 00 a. m. 



5 minutes in the 

 centra] cone, 11 

 minutes in the 

 north cone. 



h. in. s. 



1 25 00 



1 00 00 



Not taken. 



1 02 00 



Not taken. 



Maximum ; 107 feet 

 in center, oono; 

 maximum, 35 feet 

 in noith cone. 



d. h. m. s. 



2 



2 50 00 



3 







7 05 00 



4 

 5 



5 minutes in central 

 cone, 10 minutes 

 30 seconds in 

 north cone 



8 m mutes in the cen- 

 tral cone, 12 min- 

 utes, 45 seconds 

 in north cone. 



Center cone, maxi- 

 mum, 114; average 

 61. North cone, 

 maximum, 56 feet. 



Center cone, maxi- 

 mum, 108 feet ; 

 average, 59 feet. 

 North cone, maxi- 

 mum, 66 feet; av- 

 erage, 42 feet. 



5 4 06 00 

 3 11 00 



From these observations it is of course impossible to deduce the pe- 

 riod of the geyser, although it seems to have three eruptions separated 



* Report U. S. Geol. Survey for 1872, p. 245. 



