GEOLOGICAL SUEYEY OF THE TERRITORIES. 185 



is tlie sixth group, situated on a small stream flowing into the Fire- 

 Hole. They are in a large, open, prairie-like valley, which is for the 

 most part marshy. At the head of the valley there is a beautiful cascade. 

 We took the temperatures of thirty -four springs, varying from 106^ F. 

 to 198^ F., the average being 184^ F. One of the springs was strongly 

 chalybeate. The seventh group is on the Fire-Hole Eiver, about two 

 and a half miles south from our camp. Here we met with the largest 

 spring we had yet encountered. It was over 400 feet in diameter, and 

 the sinter extended in overlapping layers for a considerable distance 

 around it. Below this, about 600 feet from the river, was a second 

 huge spring, which we named the Caldron. The level of the water in 

 it was 20 feet below us, and the view of it obscured by the dense clouds 

 of steam rising from it. The glimpses we got revealed that it was of a 

 beautiful blue color. One side of the wall was broken down, and 

 thence the water flowed into the river through a number of streams, 

 forming a cascade, whose beds were lined with the sesquioxide of iron. 

 We took the temperatures of twenty of the springs, and found the 

 average to be 184° F. The lowest temperature w^as 132o F., and there 

 were but two other springs below 173° F. Oue-half of the springs 

 were above 100° F., the highest being 190^ F. The air was about 70^ 

 F. to 760 F. The lower geyser-basin comprises an area of about thirty 

 square miles, and the springs whose temperatures we took are but a 

 small part of the whole niiniber. They are divisible, like those of 

 Iceland, into three classes : 1. Those which are constantly agitated or 

 boiling. 2. Those which are agitated Quly at particular i)eriods. 3. 

 Those which are always tranquil. In the geysers the water is usually 

 placid until within a short time of the eruption, when it begins to 

 bubble and there is an escape of steam, the water rising gradually in 

 the basin until suddenly it is projected into the air. 



We left our camp in the lower basin about noon of the 4th of August, 

 proceeding up the Fire-Hole River, and in the evening pitched our tents 

 in the upper basin. This basin is not so large, occupying a space of 

 only about three square miles, and containing a less number of springs. 

 They are, however, much more active, and their craters are more beauti- 

 ful, interesting, and larger. The majority of the springs and geysers 

 are near the river, extending along it on both sides for about three miles. 

 Many of them were named by the party under Laugford and Doane, 

 who visited them in 1870. Soon after getting into camp we were treated 

 to an exhibition that was truly wonderful. Immediatel}' opposite us, 

 at the base of a small hill, a geyser threw a column of water to 

 the height of over 200 feet from the earth, which shook as the water 

 fell back into its basin. It was accompanied with a vast quantity of 

 steam. We gave it the name of the Grand Geyser. It had but one 

 more eruption during our sta^^, and that during the next night, after an 

 interval of thirty-one hours. The deposit throughout the valley is 

 siliceous, as in the lower basin. We recorded the temperatures of one 

 hundred and four springs and geysers, and these were but a few of the 

 whole number. Many of those not taken were too violently agitated 

 for us to approach them with safety. Others were so large as to be 

 beyond the reach of the thermometer. Two-thirds of tlie tempera- 

 tures taken were over 17(P F., tlie lowest being llo^ F., and the high- 

 est lOOo F. The temperature of the air was 07^ F. The principal 

 geysers were named as follows: The Soda Geyser, the Fan Geyser, 

 the 'Kiverside, the Grotto, the Pyramid, the Giant, the Punch Bowl, 

 the Grand Geyser, the Saw Mill, the Castle, the Giantess, the Bee 

 Hive, and Old Faithful. The Soda Geyser was 'two miles below our 



