PEALE.] UPPER GEYSER BASIN WHITE PYRAMID GROUP. 201 



when the water was low was 150° F,; when bulging it had increased to 

 180° F. The spring is on the edge of a platform of geyserite. 



jSTo. 4 is a flat basin with several holes (see table). It is on a plat- 

 form of grayish-white geyserite. 



No. 5. Spray Geyser. — This is probably a geyser, and should perhaps 

 have the name Comet which I have given to No. 7 provisionally. The 

 latter I saw in action while I was close to it, but one afternoon an 

 eruption Occurred in this group which I saw from a distance, and which 

 seemed greater than the eruptions I observed carefully in No. 7 on Sep- 

 tember 11. As the latter is known to be a geyser, I have for the present 

 given it the name Comet, and call this Spray Geyser. 



The mound of No. 5 is 2^ feet high and beaded on the outside. The 

 basin is 15 feet by 7 feet. It is yellow-lined, and the water had a tem- 

 perature of 199° 'F. It was boiling violently during the time I saw it, 

 and I have no doubt that it is a geyser. If it should so prove to be, I 

 propose the name Spray Geyser for it, as indicated above. 



No. 6. This is a handsome white basin in which the water is of a 

 beautiful light-blue tint. In the outer portion of the basin where the 

 water is shallow the bottom is yellow, which becomes saffron and red- 

 colored as No. 7 is approached. The border, where the overflow from 

 No. 7 comes into No. 6, is gray, and is raised about 3 inches. The outer 

 rim of No. G is continuous with the outer rim of No. 7, so that they are 

 really in one basin. The following temperatures were taken: At the 

 surface after the eruption of No 7, 165° F.; 11 feet below the surface, 

 1C90 F. A large part of the overflow during the eruption of No. 7 

 X^assed away over No. 6. 



No. 7. Comet Geyser. — This name is the one originally given to the 

 Grand by Colonel Barlow, and I have transferred it to this which, from 

 all accounts, is a geyser of some importance. It has alarge, flat, grayish, 

 white basin 'which connects with No. 6 when it is full. In about the 

 center of this basin are two mounds of yellowish-green-gray beaded 

 geyserite. The largest is on the west side, and is about 18 inches high 

 with a diameter of about 3 feet. The eastern one is only about a foot 

 in height, and has two orifices. These two mounds aj^pear to be in con- 

 stant action. Between them is a pool from which the spouting takes place. 

 Its south edge has masses of geyserite along it, like the two mounds, 

 although they are only 6 inches in height. Between the eruptions the 

 water in the pool is in ebullition. The following temperatures were 

 taken on September 11 : 



2.39 p. m. — Surface temperature, 191° F. 



2.45 p. m. — Temperature 2 feet below the surface, 199° F. 



2.51.50 p. m. — The eruption occurred. 



2.55 p. m. — Surface temperature, 18G° F. 



2.56 p. m. — Temperature 3 feet below the surface, 200° F. 

 The following are the notes of eruptions taken September 11 : 



No. 1. — 9.33,15 a. m. — The geyser spouts 25 or 30 feet at the maxi- 

 mum. An irregular splashing mass is thrown sideways and straight up 

 into the air. The duration of the eruption wa's 1 minute 15 seconds. 



No. 2. — 1.37 p. m. — Spurts about 20 feet; duration 30 seconds. 



No. 3. — 1.50.45 p. m. — Spurts 15 feet ; duration 1 minute 5 seconds. 



No. 4. — 2.10.10 p. m. — Eruption begins and lasts 55 seconds. 



No. 5. — 2.28.45 p. m. — Spouts to a height of 30 feJjt, with spurts in all 

 directions. The eruption lasts 1 minute. 



No. G. — 2.51.50 p. m. — An erui)tiou begins, lasting 55 seconds. 



