e 
166 F. V. Hayden—Hot Springs and Geysers 
entire area was covered thickly with conical mounds of various 
sizes, ranging in diameter from a few inches to a hundred feet 
or more, and these cones or hillocks were full of orifices, from 
which streams were issuing. All these little chimneys or — 
orifices were lined with the most brilliant crystals of sulphur, 
and avhen the heated crust was removed, we found the under- 
side adorned in the same manner. The basis of the deposit was 
silica, as white as snow ; but it was variegated with every shade 
of yellow from sulphur, and with scarlet or rose color from 
oxide of iron. In the distant view the appearance of the whole 
country may be not unaptly compared to a vast limekiln m 
full operation. The east branch of the Madison is almost en- 
tirely fed by water from the hot springs, and its temperature 1s 
60° or 80° all the time. The vegetation that grows along its 
branches and in the stream itself is a marvel of luxuriance. 
A broken range of hills, forming a kind of ridge, oxi : 
its terminus it is broken into several isolated butes, yao : 
€ ie 
deed, the igneous rocks on either side of both the valleys 
show plainly that during the time that the volcanic forces were 
forming very thick 
the mountain. 
