peam:.] lower geyser BASIN EGERIA SPRINGS. 181 



sketches were a little too bright. The visit of 1878, however, proved to 

 us again the truthfnlness of the i3ictares. A view of the spriug here de- 

 scribed will convince any one, no matter how skeptical, that the colors 

 cannot be exaggerated. 



As I have already stated, the spring is on the suramit of a mound, 

 which, as shown in the walls of the next spring to be described, is built 

 up of layers of the siliceous deposit. The water, which flows away from 

 the spriug in all directions, rises and falls in a series of wave-like pulsa- 

 tions, which has formed a succession of terraces, especiallj^ at the south, 

 end, where they have formed steps several inches in height. The small 

 raised rim is a series of beautiful large scallops. The temperature of 

 the water at the north end near the edge was 140° F. 



Our observations do not show whether or not there is any periodicity 

 in the activity of this spring, but the indications are that it is not a gey- 

 ser, although closer observations are needed to prove the fact. 



No. 2. Turquoise Spring. — This is a deep, blue tinted, square spring, 

 measuring 100 by 100 feet, below Ko. 1 and to the left of No. 6. The color 

 is intense in hue. ISTear the outlet is a white shelf projecting a short dis- 

 tance into the spring, and over it the water is shallow. The tempera- 

 ture of the water at the south edge is 171° F. The comx)aratively low 

 temperature is probably due to the fact that part of the water is de- 

 rived from the overflow of Ko. 1. On the map of 1871 1 find the tem- 

 perature of 190° F. given for a spring which appears to occupy about 

 the position of this one, but the map is not correct enough to identify 

 it positively. The water outlet is like a trough, 6 or 8 inches in depth 

 and 18 inches to 2 feet in width. It is of a brilliant white on the bottom, 

 with white and yellow edges. As the river is ai^proached the channel is 

 yellow, with a salmon-color edge. It joins one of the outlets from ISTo. 3, 

 and through it there is a rapid and strong flow of water, a large part of 

 which is actually from the spring, and not from the overflow of No. 1. 

 The name has been given from the tint of the water, which is the blue 

 of the turquoise. 



No. 3. Clijf Cal(lro7i or Excelsior Geyser (Plate XIII). — Equally inter- 

 esting with the Grand Prismatic Spring is the one to which I have given 

 the name of Clifl" Caldron. We called it the caldron in 1871, to which 

 I have added the name given it by Professor Comstock in 1873. It is an 

 immense pit, of rather irregular outline, 330 feet in length and 200 feet 

 wide at the widest part. The water is of a deep-blue tint and is intensely 

 agitated all the time, dense clouds of steam constantly ascending from it. 

 It is only when the breeze wafts this aside that we can see the surface 

 of the water, which is 15 or 20 feet below the level surrounding. The 

 walls are ijerpeiidicular, clifl"-like, and sometimes overhang, and are found 

 on three sides, having been worn awaj'^ at the outlet. The deposit in 

 which this pit is cut is laminated old spring deposits, showing that this 

 spriug is secondary in its formation. It is probable that when the lam- 

 inated deposit was laid down, the spriug on the summit (No. 1) was the 

 main spring and of vastly greater extent. It appears that this spring 

 brolce out near the river and has been working backward, the constant 

 undermining of the deposits constantly enlarging the basin of the spring. 

 Large masses have broken oft" the edge and have tumbled in. Towards 

 the river the walls become less high, as the top has the slope of the mound 

 which is in that direction. There is an immense column of water pour- 

 ing from the spring, which soon sjireads out on terraces and finally pours 

 over the marginal slope in two well-defined channels. Some of the 

 u])per channels are small and narrow^, and others broad, all brilliantly 

 colored, yellow, orange, red, and rose tints being liberally displayed on 



