238 GEOLOGICAL SURVEY OF THE TERRITORIES. 



no other is important. A little to the left, as we advance across the 

 valley, upon a very flat mound, we find a cluster of four large and sev- 

 eral small vents. The beady deposit about them is very pretty. One 

 of the larger vents apparently spouts moderately, though not frequently. 

 The temperatures vary from 191° to 193°. A few rods farther on, we 

 come to a truncated conical mound, rising about 22 feet above the creek, 

 on whose bank it stands. Upon the summit is a shallow, nearly circu- 

 lar, pool, about nine feet across, bordered with au exquisite frilled edging^ 

 from four to six inches high from the surface of the mound. From this, 

 three or four small streams flow over the edge and down the side of the 

 mound through deeply-imbedded channels. This appears to be a strong 

 spouter, and is probably the source of the tall column of steam before 

 mentioued. The creek cuts into the base of the mound ou the north 

 and west sides, and will probably before many years cut into the central 

 tube and cause the eruptions to take a horizontal direction, as well as, 

 or instead of, a vertical one. The temperature is 198°. A few rods 

 farther, on the west side of the creek, stands another mound of the same 

 form, but from two to three feet lower, and its pool is a little less regu- 

 lar. It has also a small conical vent just outside the pool. This has 

 probably been a strong spouter, but I think that it does not now erupt ; 

 temperature, 197°. The ornamentation about these two pools appeared 

 to me, as well as to others, to be the most beautiful of any in the whole 

 basin. Still going westward, we find, in the extreme edge of the valley, 

 on the top of a low mound, a cluster of four vents, from one to two and 

 a half feet across, quite irregular in shape, and all boiling too violently 

 to allow one to take the temperatures. All were surrounded by bead-like 

 incrustations. I judge that they all spout moderately. Along this 

 western side of the valley, the base of the hill is thoroughly saturated 

 by the flow of very numerous cold and slightly warm springs. About 

 a quarter-mile above the mounds, we found the creek flowing rapidly in 

 a narrow deep channel with muddy banks, and not easily crossed. Its 

 temperature of 52°, and the entire absence of the siliceous fragments 

 elsewhere so abundant, satisfied us that no hot springs exist in the upper 

 part of its valley. Returning to our former crossing, between the high 

 mounds, we turned south along the east side of the valley. Here is a 

 low mound on the foot of the spur, which had shown only the smallest 

 whiff's of steam, and had been supposed to be nearly extinct; but, upon 

 approaching the vent, we found a deep basin, apparently hollowed out 

 of dark basalt, but really lined with a smooth-surfaced dark reddish-, 

 brown siliceous deposit, made by the spring itself. TLis is very different 

 in color from any other known in the whole Fire-Hole Valley, and was 

 called the Iron Pot. It was boiling moderately at about six feet below" 

 the surface, when first seen, but afterward filled nearly to the surface.^ 

 Its temperature could not be obtained. The form of the pool is ovate, 

 about 7 feet by 5 at the lowest level seen, and expanding above to about 

 10 feet by 7. Though it may often fill its pool, it probably does not 

 spout much. A hundred yards farther south, along the foot of the 

 spur, there is an irregularly-oblong, steaming pool, about 100 feet by 30, 

 and from 15 to 20 feet deep, with two or three deeper pits. At the east 

 end it boils constantly and sends off dense clouds of steam. Along the 

 edge at this end, the ordinary pearly-beaded deposits are abundant, while 

 a few inches within the rim, and sometimes attached to it, were numer- 

 ous coral or mushroom-like forms with broad tops expanding from a 

 slender base. The portions of these forms which are toward the steam, 

 and so are constantly moist, are covered with small points, re- 

 minding one of the polyp-cells of the Madrepores, while the oppo- 



