1876.] 
Scheme of Water Supply. 
309 
Upper Greensand. 
The water from the Upper Greensand is probably a little 
less hard than that from the Chalk. 
Lower Greensand . 
The water from this formation is generally considered un- 
exceptionable, and decidedly “ soft.” Samples taken from 
five localities give a mean result of 7*9 of solid matter in 
100,000 parts of water. Mr. Bateman, C.E.,* speaks of the 
water from this formation in the basin of the Wey as being 
of the greatest purity ; and, as the sands are generally loose 
and incoherent, they absorb nearly all the rain which falls 
on their surface, except that given off by evaporation or 
imbibed by vegetation. 
Enormous quantities of water are absorbed by this forma° 
tion, where, as in Surrey and Kent, it is largely developed; 
and to such an extent are they capable of being rendered 
available that Mr. Lucas proposes, by means of tunnelling, 
to render them available for the supply of London. t In 
Bedfordshire, Bucks, and Berks, as also in the S.YV. of 
England, the formation attains large proportions, and con- 
tains bands of siliceous iron ore, which to some extent 
affedts the water. Exposure to the air, however, causes the 
iron to be precipitated. 
Oolite Limestones . 
The waters from these formations are all more or less 
hard, yet less so than those from the Chalk, and of course 
where the source is the sandy strata which accompany the 
limestones of the Portland Oolite, the Great and Inferior 
Oolites, &c. 5 the qualities of the water will be found to 
vary accordingly. Of the proportion of solid matter in the 
waters of the Oolites that found in the fine springs of South 
Cerney, near Cirencester, which rise along the line of a large 
fault, may be taken as a sample. The total amount of 
solid matter was found to be 18 grains per gallon, of which 
1*25 was organic.! 
The water from the Seven Springs near Cheltenham, from 
the Inferior Oolite, gave 6 grains per gallon, of which 
2 grains consisted of organic matter. || 
* Report contained in a Return to an Order of the House of Lords, iS'ja, 
No. 258. 
Horizontal Wells, by j. LuCas, F.G.S. (1874). 
% Analysis, by J. Horsley, F.C.S. Appended to Report on the Water* 
Supply of Cheltenham, by Dr. Wright, F.G.S. 
! j Ibid. See, also, Prof. Prestwich “ On the Geological Conditions 
affedting the Water-supply of Houses, &c.” (Parker and Co*, Oxford), 1876. 
