194 EEPORT UNITED STATES GEOLOGICAL SURVEY. 



Fourth spurt at 12i^. 20™.30« p. m. ; stopped at the end of 2 minutes 10 

 seconds. 



The intervals of quiet are 30 seconds, 30 seconds, and 1 minute 30 

 seconds. After this the steam escaped gently. 



The third period the height reached was not very great, but on the 

 fourth it was high. None of the spurts, however, were accurately meas- 

 ured. Only one orifice spouted. The one farthest from the river gave 

 off a slight amount of steam but no water, and the " perpetual spouter" 

 steamed during the entire eruption. The column was not perpendicular 

 but slanted toward the river. The amount of water ejected was slight 

 and was largely broken into spray. The Riverside was quiet during 

 the action. 



The following shows the comparison of the different years : 



Langford, 1870 — 10 to 30 minutes in duration. 



Comstock, 1873 — 13 minutes in duration. 



Peale, 1878 — 9 minutes in duration. 



Ko. 22. Riverside Geyser. — This double geyser received its name in 

 1871. It does not appear to have been seen in action in 1870. It is 450 

 feet above (south of) the Fan, on the same side of the river, just above 

 the bend. It has a low, irregular mound with a chimney in the center. 

 It has two orifices and spouts at intervals that are undetermined, the 

 column reaching a height of 80 to 90 feet, as estimated in 1871. It is 

 somewhat out of the way, and unless seen in action would not be tak^^n 

 for a geyser of any importance, as there is little about its crater to at- 

 tract attention. 



In 1873 Professor Comstock saw it in action, and describes the erup- 

 tion as follows : 



A little below the grotto, across the river, a geyser which is situated near the edge 

 of the stream began to spout at 2.43 p. m. This is known as the Riverside Geyser. A 

 jet of fie spray was very suddenly thrown more than 30 feet into the air, which con- 

 tinued quite steadily xmtil 2.47.5 \). m., when it ceased acting for one-holf minute ; 

 then it played weakly for 2 miuntes, ceasing again for half a minute ; then played 

 again rather vigorously until 2.53 p. m. {2^ minutes). At 2.45 p. m. it roared loudly 

 and became quiet at 2.56 p. m., after which no action occurred. 



The duration of this eruption was 13 minutes. The simultaneous 

 action with the Fan was probably only a coincidence, as during the 

 eruption of the latter, seen by myself in 1878, the Riverside was quiet. 



In 1877 General Sherman's party saw the Riverside in action once,* 

 and Colonel Poe says " it astonished us by the duration of its eruption, 

 which was more than 10 minutes." t 



GIANT GROUP. 



Although this group is small as compared with the other groups of 

 the basin, it contains two first-class geysers, and one minor geyser that 

 has a cone of considerable beauty. There are three clusters of springs, 

 the principal one being on the platform of the Giant Geyser, the second 

 on the platform of the Oblong Geyser, and the third on the opposite 

 side of the river. The latter is separated from the Grand Group by a 

 narrow strip of timber, or it might be included with the latter. 



The springs are sufficiently described in the table which follows, but 

 the geysers deserve special mention, which will be given after the table. 

 Temperatures taken in the cluster on the east side of the river in 1871 

 were 172° F. to 196° F. Temperatures on the platform with the Giant, 

 taken in 1872, ranged from 182° F. to 196° F. In the Giant the same 



* Reports of inspection made in the summer of 1877, Sec, page 36. 

 Mbid., page 78. 



