ON THE CIRCULATION OF UNDERGROUND "WATERS. 383 



tigation, which now include the whole of the strata lying between the 

 Carboniferous and Cretaceous rocks. 



Your Committee have a large amount of information promised them 

 of works and sinkings now in operation by various engineers, and 

 especially by officers of the Government Geological Survey, who are 

 now working over the Yorkshire and Lincolnshire Oolitic districts ; and 

 they endorse the opinion expressed by Mr. Edwin Chadwick, C.B., at the 

 Congress on Water Supply held by the Society of Arts, as to the great 

 value of the map of the Survey as a basis for investigation in questions of 

 water supply. 



Your Reporter laid before the Congress a table showing the area of 

 each of the geological formations in each river basin, from which it 

 appears that of formations yielding — 



Subterranean waters. 

 Square miles. 



• Permian and Trias 8,645 



Oolite 6,071 



Hastings sands, Greensand and chalk ...., 11,371 



26,687 



Moorland waters. 

 Square miles. 

 Granite, Metamorpkic rocks, Cambrian, Silurian, 



and Devonian 11,455 



Carboniferous rocks (without the Carboniferous 



limestone) 10,080 



21,535 



Probably four-fifths of the area of permeable rocks in the first list would 

 yield unpolluted water, and would receive into their mass not less than ten 

 to fifteen inches annually, or a quantity, if six inches only were yielded up 

 in wells, of no less than 240,000 gallons per day for each square mile of 

 surface, and in many districts double this quantity, giving a total for 

 England and Wales far in excess of that required for drinking and manu- 

 facturing purposes. 



Of the Moorland area it is hardly the province of your Committee to 

 speak, but they cannot but call attention to the costly legislation that all 

 extensive gravitation schemes incur, whether taken from natural lakes, 

 as the proposed Thirlmere scheme for Manchester, or from artificial reser- 

 voirs, as the proposed supply for Liverpool from the sources of the Severn ; 

 and they would call attention to the fact that the Select Committee on 

 the Manchester Corporation Water Bill recognised the importance of the 

 opinion expressed by the Duke of Richmond's Commission in 1868-69, 

 " That it appears to ns that the Legislature should always jealously watch 

 any proposal for a town taking water from a gathering ground at a 

 distance from it, lest by so doing it may deprive other places neai'er to 

 such gathering ground of their more natural source of supply." 



Cases doubtless exist, to meet which it will be necessary to go to these 

 sources, especially where the populations have been accustomed to soft 

 water, and it would be dangerous to suddenly change the character of the 

 supply. But in the Midland districts, lying on the Secondary rocks, the 

 inhabitants are accustomed to hard water, the quality of which the labours 



