CHAPTER VI. 
Of Boring or Digging for Water on the “Llano Estacadof 
The only natural obstacle presented by this route is the absence of water on the “Staked 
Plain,” and to obviate this difficulty two methods can be proposed, and they will be considered 
separately. The first is by digging wells, or constructing artificial tanks, and the second 
by boring astesian wells. 
To justify the opinions I shall express as to the practicability and relative advantages of 
either process, a brief sketch of the conditions necessary to success in each case would seem to 
be necessary. 
There are two classes of springs from which the two descriptions of wells above mentioned 
are supplied—first the shallow, and, second, the deep-seated springs. The first of these is 
dependent for its supply of water upon the rains which fall upon the surface of the limited 
district of country in which these springs are found. 
The water falling upon the surface of the ground percolates through the soil until it encoun¬ 
ters a stratum of rock or clay, impervious to water, and follows the lowest lines of this stratum 
until it appears at the surface. It follows from these conditions that shallow springs are 
directly affected by the quantity of water which falls in the immediate neighborhood, and in 
consequence, during seasons of drought, they frequently become dry. 
There are, of course, basins or circumscribed tracts of land, in which the immediate surface 
of the ground is’impervious to water, and in such districts we find lakes, ponds, or swamps. 
Deep-seated springs, on the contrary, are found beneath the impermeable stratum, which is 
the base of the shallow springs, and are only affected by the rain-fall remote from the points 
at which the springs burst out. The strata of the earth, originally deposited in a horizontal 
position, have been upheaved by natural causes along the lines of the mountain ranges, and the 
strata thus dislocated present over many miles of country, and most generally in the vicinity of 
the mountains, their edges exposed upon the surface. 
Where the strata are composed of alternate beds of permeable and impermeable character, 
the rain which falls upon the edges exposed by dislocations, and the descent of the water occa¬ 
sioned by the melting of the snows on the mountains, would completely saturate the permea¬ 
ble stratum, and the water would continue to follow its line of greatest descent. 
If we suppose a permeable stratum of this character to be interposed between two impermea¬ 
ble strata, the water must continue between them, until the stratum containing it is exposed at 
the surface at a lower level. 
By boring, therefore, at any point of the surface of the upper stratum, water would be pro¬ 
cured as soon as the water-bearing stratum was reached, which would rise in the shaft to the 
height of the point of exposure of the stratum at the upper surface, less friction and loss of 
water through fissures. 
There are many circumstances to qualify this state of things, such as “faults,” (or interrup¬ 
tion of the continuity of the strata by breaks,) the giving out, as is sometimes the case, of the 
water-bearing stratum, &c. &c.; but most generally there is no great difficulty in ascertaining 
with some considerable certainty the prospects of success in these borings, before commencing 
the work. 
These deep-seated springs are not nearly so much affected by the rain-fall as the land springs, 
