264 MR. E. HULL ON THE NEW RED SANDSTONE, ETC., 



that on both sides of the Mersey the water contained in 

 the New Red Sandstone acts as a counterpoise to that of the 

 sea, so that when, by pumping, the water-level of the rock 

 is lowered, and the pressure removed, the sea forces a 

 passage for itself through the strata in order to restore the 

 balance. 



But the most conclusive proof of the extreme porousness 

 of the formation is derived from the large quantity of water 

 which it is capable of yielding from a single well, and 

 which therefore must be drawn from a considerable area. 

 As instances we may mention the Windsor Well at Liver- 

 pool, which yields 1,103,000 gallons per day; the Green 

 Lane Well, which gives no less than 3,321,000 gallons ; and 

 the Gorton Well, near Manchester, 864,000 gallons. It 

 has also been found that the supply increases with the 

 depth, of course in various proportions, as a larger area is 

 thereby drained. This is a most valuable property of the 

 formation. In other geological formations composed of 

 constantly varying materials, the effect of increasing the 

 depth might be to pass from a water-bearing stratum, such 

 as sandstone or limestone, to one which contains no water 

 at all, such as shale ; but it is otherwise with the New Red 

 Sandstone ; and thus, when a small supply only is required 

 for a small town or a factory, that supply may be increased 

 by deepening the well when the increase of demand so 

 requires. 



For the purposes here referred to, there are no forma- 

 tions in England better adapted than the New Red Sand- 

 stone ; for if we compare with it the Chalk and Lower 

 Greensand, the great water-bearing strata of the South 

 of England, it must be allowed to excel the former 

 in the greater softness of the water, and the latter in 

 having a tenfold greater horizontal and vertical develop- 

 ment. 



The freedom with which water can percolate both late- 



