OF ARKANSAS. 61 
millis, at this point, with its two run of 40 inch stones, it attracts the 
custom of farmers living 30 or 40 miles distant, who throng to its door— 
even though they may have to wait days and nights for their turn to come 
round. ‘ 
The accompanying sketch [plate No. 5,] represents the present mill, 
looking north over the expanse of water, forming the source of this cele- 
brated spring. 
The water of this remarkable fountain, remains at a nearly uniform 
temperature, never freezing in winter. On the 17th of December, 1857, 
the temperature of the air being 17 deg. Fahrenheit, the spring showed 
only 57 deg. Fahrenheit. But the average temperature, when the ther- 
mometer is sunk deep in the spring, will probably be found to be 60 deg. 
The extent of the range of extreme low and high water, is but 3 to 4 
inches, so that the variation in the supply of water is very slight. 
A large proportion of the water now runs to waste, the present mill 
only requiring a limited supply; but, if it were all saved, which it could 
very easily be, there would be enough for many grist-mills, as well as 
woolen factories, which would be well adapted to the resources of’ the 
country; since both the climate and herbage seem to be well suited to 
raising sheep. At least, the small flocks of sheep, seen in the range, 
appeared both healthy and vigorous. 
The water is generally clear and limpid; it only becomes slightly muddy 
after long continued rains. From 10 to 11 feet of fall can be obtained 
between the fountain-head and the present site of the dam. 
The principal outcrop of rock, is a white silico-calcareous rock, splitting 
with a slaty fracture, and presenting dendritic markings on its surface. 
Locally, large quantities of calcareous tufa have accumulated, and are 
still forming in creeks and recesses around the head of the spring; 
deposited from the water, partly on account of the loss of a portion of 
its carbonic acid, which is dissipated into the atmosphere as these calca- 
reous waters reach the surface, and partly by gradual evaporation. 
Varieties of chert, hornstone, and porous buhrstones, form the most con- 
spicuous rocks in the ridges of the northern part of Fulton county: these 
repose on limestones, mostly of a siliceous character, with segregations 
and interpolations of chert, sandstone and calciferous sandrocks. 
It is supposed that the original source of the Mammoth spring is 
Howel’s valley, Oregon county, Missouri, since the waters of this valley, 
which is eight miles wide and thirty miles long, are not known to have 
any external outlet, losing themselves in sink-holes and subterranean 
caverns and passages. Uniting, as is supposed, near the southern boun- 
dary of Missouri, they again burst forth to the day through caverns and 
