306 Scheme of Water Supply . [July, 
nication, I wish to premise that I have no intention of 
dealing with the question of water-supply to large towns, 
or any of those places which would come under the head of 
“Urban Sanitary Districts” of the Public Health Aft of 1872. 
Such districts and towns may well be relegated to the care 
of their respective sanitary authorities, guided by a corps of 
engineers, who are ever ready to find water if only the 
money for the purpose is forthcoming. It is to the more 
humble and greatly negledted villages, hamlets, and country 
parishes of the central counties my observations are in- 
tended to apply, with a view of showing that the means are 
generally available for providing them (where required) 
with that essential concomitant to health, decency, and 
comfort— good water. 
Physical Considerations. 
Though large portions of those districts of England re- 
ferred to in this paper are destitute of hills, — the birth-places 
of springs and fountains, — yet it happens that the geological 
formations are arranged so as to constitute underground 
reservoirs for a large proportion of the ordinary rainfall, 
which can be rendered available by wells of greater or less 
depth. These districts are composed of the Mesozoic (or 
Secondary) formations, consisting of alternating beds of 
permeable, or water-bearing, and impermeable, or dry, 
strata ; generally arranged with such a moderate dip as to 
spread over large areas, and capable of retaining on the one 
hand, or throwing off on the other, a certain proportion of 
rainfall, varying in amount according to circumstances. 
The water-bearing strata consist of sandstones and lime- 
stones of various kinds ; the impermeable, or non-water- 
bearing, of clays and shales ; and it is therefore evident that 
any system of water-supply applicable in the one case would 
not be so in the other, and that the subject divides itself into 
two heads accordingly. 
Let us, however, before proceeding further, take a rapid 
view of the formations referred to in descending order, 
commencing with the Lower Tertiary strata of the London 
Basin, which form the upper limit of our survey.* 
* The supply of the London district and the water-bearing strata of the 
Thames Valley, which is beyond the scope of the present paper, has been 
admirably treated by Prof. Prestwich, in his Anniversary Address to the 
Geological Society of London (1872), to which the reader is referred. See 
also “ Horizontal Wells,” by J. Lucas, F.G.S., containing a remarkable and 
original scheme of water-supply, by intercepting the underground waters by 
tunnelling. Also, “ Sixth Report of Commissioners on the Pollution of Rivers, 
and the observations thereon,” by Mr. John Evans, F.R.S. (Quart. Journ. 
Geol. Soc., vol. xxxii., p. 115). 
