PEALKJ GIBBON GEYSER BASIN. 129 



the evidences of the flow of water. This may have occurred when the 

 vent burst open. 



The description just given is from my field-notes for 1878. Since 

 writing them out Mr. Norris informs me that in 1875 the vent had no 

 existence, and in his report for 1879 he gives the date of its formation 

 as August 11, 1878. In the same report also he says (on page 16) 

 that it has settled down to business as a very powerful flowing ge3^ser, 

 which has a double period ; one eruption occurring every half hour, and 

 projecting the water to a height of 30 feet, and the main eruption occur- 

 ring every six or seven days, the action being long continued, and the 

 column attaining a height of nearly 100 feet. When we saw it in 1878 

 there was no water in sight, and the steam escaped in a steady column. 

 This promises to be the most interesting geyser in the Park, as it will 

 afibrd most important data as to the building of the deposits and the 

 age of the geysers. This subject will be discussed in another portion 

 of the report. Ttie study of the future of this geyser and of the "New 

 Geyser," to be described farther on, promises to be most interesting. 



i^o. 44 is a large gray mud-pot, 20 by 23 feet, situated in the valley 

 below No. 43. It boils vigorously. 



No. 45. Echinus Geyser. — This was so named because the pebbles 

 around the basin have some resemblance to the spine-covered sea 

 urchin. The basin is about 40 feet in diameter, and throws a mass of 

 water 15 to 20 feet into the air at intervals the length of which we were 

 unable to determine, on account of our short stay in the basin. The 

 border of the spring is gray and red or reddish brown, coated with black 

 and bluish gray spinous-like processes. The coating of geyserite is thin, 

 and the underlying rocks are exposed at places, as though this were a 

 comparatively new geyser. Below the basin deep red and maroon colored 

 terraces spread for some distance from the geyser, and it is probable 

 that the geyser has at times eruptions on a grand scale. The eruption 

 which we witnessed lasted about three minutes. I think this geyser 

 marks a step in geyseric action beyond that shown by No. 73, which 

 itself marks a stage beyond that shown in No. 43. 



No. 46. Vermillion Sj^ring. — This is a bright red muddy spring 8 feet 

 in diameter. 



No. 47 is a large sulphur spring in a basin about 35 feet in diameter, 

 with several centers of ebullition. 



No. 48. Pond-like turbid pool boiling in the center. 



No. 49. Large greenish pool with several centers of ebullition. 



No. 50. Muddy steam vent on the side of the hill back of No. 48. 

 The opening is 3 feet in diameter. 



No. 51 is a large pool about 30 feet in width with three centers of 

 ebullition. Back of it is a gray boiling mudhole 6 by 10 feet. 



No. 52 is a deserted geyser hole with a little water at the bottom. 

 There are steam vents near it. 



No. 53 is a bubbling spring 2 feet in diameter. Back of it are sulphur 

 springs. 



No. 54. Double J)ulger. — Two bulging springs with rims and a pool 

 back of them. Below, it is a large pond. 



No. 55. Febhle Oeyser. — This, as far as we could determine, is one of 

 the most important geysers in the basin. It is a tube 6 inches by 2 

 feet, in a mound of hard semi- translucent geyserite. When we visited 

 it on the 13th of Sei)tember there was no water visible, but the surround- 

 ing basin gave evidence that it is a geyser. Its name was given to it 

 from the abundance of resetted pebbles in the basin outside of the 

 tube. On the 14th we saw from a distance two erux^tions of this geyser, 



9 Hj PT II 



