560 SPRINGS CAUSED BY FAULTS. 
overflows incessantly in the form of Springs, that 
carry with them fertility into the adjacent val- 
leys. (See PI. 67, fig. 1 , S.) 
The discharges of water from these reservoirs 
are much facilitated, and increased in number, 
by the occurrence of Faults or Fractures that in- 
tersect the strata.* 
There are two systems of Springs which have 
their origin in Faults, the one supplied by water 
descending from the higher regions of strata ad- 
jacent to a fault, by which it is simply intercepted 
in its descent, and diverted to the surface in the 
form of perennial springs ; (see PI. 67, fig. 1 , H.) 
the other maintained by water ascending from 
below by Hydrostatic pressure, (as in Artesian 
Wells,) and derived from strata, which at their 
contact with the fault, are often at a great depth ; 
* Mr. Townsend, in his Chapter on Springs, states, that there 
are six distinct systems of springs in the neighbourhood of Bath, 
which issue from as many regular strata of subterraneous water, 
formed by filtration through either sand or porous rocks, and 
placed each upon its subjacent bed of clay. From these, one 
system of springs is produced by overflowing in the direction 
towards which the strata are inclined, or have their dip ; whilst 
another system results from the dislocation of the strata, and 
breaks out laterally through the fractures by which they are in- 
tersected. 
It is stated by Mr. Hopkins, (Phil. Mag. Aug. 1834, p. 131), 
that all the great springs in the Lime-stone District of Derbyshire 
are found in conjunction with great Faults, “ I do not recollect 
(says he) a single exception to this rule, for I believe in every in- 
stance where 1 observed a powerful spring, I had independent 
evidence of the existence of a great fault.” 
V 
