148 



GEOLOGICAL SURVEY OF THE TERRITORIES. 



pal springs in tlie group. The peculiar lamination Of the deposit at the 

 edges is well shown. The elevation at the lower end of the upper basin 

 is 7,321 feet, and at Old Faithful, at the upper end, 7,397 feet. 



On the morning of August 17 all the specimens were sent to Virginia 

 City by pack-train, and in the afternoon, in company with Messrs. 

 Brown^ Sloane, and Bingham, 1 pro'ceeded to the upper basin to make 

 observations on its principal geysers. These are named as follows : Old 

 Faithful, Bee-Hive, Giantess, Oastle, Grand, Turban, Saw-Mill, Giant, 

 Grotto, the Riverside, the Fan, and the Soda Geyser. All of these, save 

 the Giant and the Fan, were seen in action this year. Our stay being 

 but three days in length necessarily renders the observations somewhat 

 incomplete. There is but little doubt that a longer stay would develop 

 many new geysers. We spent one day at Old Faithful, as it spouts more 

 frequently than any of the others, and is also at the head of the valley, 

 making a good starting-jjoint. I will refer to them all separately below. 



Old Faithful. — The mouth of this geyser slopes inward, measuring 

 outside 8 feet by 4 feet and inside G feet by 2 feet. It is in a mound of 

 geyserite that rises 11 feet 11 inches above the surrounding level, and 

 measures at the base 145 feet by 215 feet and at the top 51 feet by 20 

 feet. The mound is arranged in a series of small basins, rising one 

 above the other, in which the water, beautifully clear, stands after the 

 eruptions. The edges of these basins, as well as the throat of the gey- 

 ser tube, are ornamented with bead-like silica. We tried to sound the 

 depth of the geyser-tube, and after letting out the entire length of rope, 

 300 feet, and withdrawing it, we found the end completely tangled, 

 which was the case in every attempt. It was impossible to get the 

 temperature of the water, for immediately after the eruption the water 

 sank out of sight, and at other times there was so much steam escaping 

 that we could not even look into the tube. There are four conical 

 mounds about Old Faithful that were probably geysers at some time in 

 the past. The eruptions of the geyser commence with a few abortive 

 attempts, followed by a rapid succession of jets, which soon reach the 



maximum, and then gradually subside and are followed 



by a slight 



escape of steam. We measured a base-line of 100 feet, and Mr. Brown 

 was able to get the heights of five eruptions, although there were alto- 

 gether seventeen witnessed during our stay, as follows : 



