AS SOURCES OF WATER-SUPPLY FOR TOWNS. 269 



point is near tlie centre of a trougli or half-basin of New 

 Red Sandstone. The hills of this formation rise in a semi- 

 circle around it^ and towards this point the strata dip. The 

 rock is generally very incoherent, and nearly all the rain 

 which falls within a radius of a mile and upwards must, 

 I concluded, flow in the direction of the point selected. 

 These expectations were fully verified. A 4-inch bore 

 having been sunk only 148 feet, a column of water ascended 

 with force to a height of 4 feet. It was at first strongly 

 impregnated with iron, but gradually became limpid and 

 clear, and has flowed ever since. A well is now being 

 sunk, and the water will be carried by gravitation to Crewe 

 in pipes. 



Faults or dislocations in this formation do not act as 

 barriers for preventing the underground flow of the water, 

 as in the case of coal-mines. They simply retard its flow 

 through the strata, or form ducts along which to guide it. 

 For this reason the lines of dislocation ofifer favourable sites 

 for wells. 



The New E-ed Sandstone is frequently underlain by im- 

 pervious clays or marls belonging to the coal-measures or 

 Permian beds. In such cases the water must accumulate 

 towards the bottom of the sandstone, as its further descent 

 is arrested. When this arrangement of the beds takes 

 place, the prospect of a large supply may be considered 

 favourable. The supply will also be influenced by other 

 causes, such as the continuous area of the formation, and 

 the presence or absence of drift-deposits overlying the sand- 

 stone. A thick coating of boulder-clay probably prevents 

 the rain ever reaching the rock beneath it. 



In conclusion, I think we may assert with confidence 

 that the value of the New Red Sandstone as a source of 

 water-supply is as yet imperfectly appreciated, and that 

 many of the towns still sufifering from the want of that 

 most necessary element, good water, would do well to 



