188 REPORT UNITED STATES GEOLOGICAL SURVEY. 



Basin are described, beginning with the Soda Geyser Group, which is 

 the most northern and the first met with on the way up from the Lower 

 Basin. 



The best camping place in the Upper Basin is on the south side of 

 the marsh that lies on the west side of the river, opposite the Giantess 

 Group. From here Old Faithful, Bee Hive, Giantess, Trinity, Mobe, 

 Castle, and Grand can all be seen. It was here that we had our station 

 in 1878 for measuring the heights of the columns of water. 



SODA GEYSER GROUP. 



This name is given to a group of springs, including several small 

 spoutera, situated below the mouth of the Little Fire Hole Eiver. The 

 majority of the springs are on the west side, about 15 feet above the river 

 level, although one of the most important is located on the east side at an 

 elevation of about 30 feet above the Fire Hole. These springs were not 

 closely examined in 1878, as our time was devoted to the principal gey- 

 sers in the main part of the basin. 



On the west side the principal geyser is the Soda Geyser, which spouts 

 about every 10 minutes. It was named in 1871 by the topographer, who 

 fancied a resemblance in its jet to the jet of a soda fountain. There are 

 several other small geysers near this, but their periods are not linown. 

 In a group of springs west of the Soda Geyser, the following tempera- 

 tures were taken in 1871: 164° F., 180° F., 194° F. The following were 

 in springs south of the geyser: 140° F., 154° F. 



On the east side there is only one that deserves the name of geyser, 

 and this is on the summit of the mound. 



Caulifloiver Spring. — It is bordered by cauliflower-like forms of green- 

 ish-gray geyserite. The water flows from the spring in several small 

 streams, the bed of each one being of a bright orange coloi. This is 

 probably the sj^ring described as follows by Professor Comstock : 



One of the largest, however, at the summit of the hill has formed a bordering rim 

 at some distance outside of the edge of the original bowl, so as to wall in a large por- 

 tion of the water, making it, as it were, a shallow pond about the inner cup. This fring- 

 ing pool is mainly upon the drainage side of the spring, leaving the main bowl nearer 

 the opposite edge. 



Professor Comstock mentions seven thermal springs of importance at 

 this place. Temperatures taken here in 1871 were, 146° F., 168° F., 

 170O F., 180O F., 188° F., 152° F., and 180° F. 



RIYER GROUP. 



This group includes the springs on both sides of the river, from a 

 short distance above the mouth of the Little Fire Hole to the point 

 where the river bends from its eastern course to a northwest course — a 

 distance of 800 yards. The springs are not definitely separated from 

 those of the Soda Geyser Group on the east side of the river, but 

 may for the purposes of description be considered as a distinct group. 

 There are about seven springs on the left bank, with temperatures of 

 136° to 190° F. Two of them are spouting springs. On the right bank 

 there are about a dozen springs, several of which are minor geysers. 

 To the upper or southern one we gave the name Eestless Geyser, 

 although its periods are not known. The temperatures here range 

 from 138° F. to 188° F. We were obliged to i)ass these springs hastily, 

 so that sufficient data to catalogue them were not obtained. Some of 



