WATER SUPPLY. 315 
junction with the variable beds grouped, for the sake of con- 
enience, with the Inferior Oolite Series. Accounts of these 
springs will be given in the Memoir dealing with the Oolites. 
Some of the beds of much-jointed paper-shale in the lower part of 
the Upper Lias of Gloucestershire, allpw water to freely pass 
through them.* 
The Lower Lias limestones yield a variable supply of water, 
but although the strata attain a thickness varying from 20 to 
nearly 200 feet, we have no records of any very copious supply 
being yielded. Constant supplies of water are obtained from the 
Lower Lias, in a well 129 feet deep, at Somerton ; and at 
Twerton coal-pit near Bath, a spring in the Lower Lias, at a 
depth of 72 feet, yielded 16,800 gallons of water per day. This 
water was saline, t (See p. 321.) A boring at Shepton Mallet 
carried to a depth of 98 feet, found no water. 
Many of the springs that issue are very permanent, and in 
seasons of long drought, they continue to yield a supply. Such 
is the case on the Glamorganshire coast near Southerndown. 
Owing, however, to the alternation of clays with the limestones, 
percolation is slow, and no large bodies of water are likely to be 
stored up in the mass of the strata. 
A well sunk at Harbury, in Warwickshire, to a depth of 37 
feet in the Lower Lias limestones, yielded 90 gallons of water per 
hour. Higher beds in the Lower Lias occasionally yield limited 
supplies of water. Thus at Saxby, near Melton Mowbray, a yield 
of about 5,000 gallons per day was met with in limestones that 
occur in the clays at a depth of 225 to 240 feet. The water rose 
to within 4 feet of the surface. 
The Marlstone and underlying sandy beds of the Middle Lias 
are usually water-bearing strata, 
In the south of England the sands beneath the thin representa- 
tive of the Marlstone are the chief holders of water, as at 
Glastonbury. The Marlstone, and the Basement-beds of the 
Upper Lias, yield supplies suitable for cottages as in the neighbour- 
hood of Yeovil ; and sometimes a good supply has been obtained, 
as at the Yeovil gas-works, where the water rose to the surface. 
In South Gloucestershire the Marlstone is poorly represented, 
but it becomes more important near Wotton-under-Edge. East- 
wards again it is variable in character. 
At Kingham Hill, near Chipping Norton, a well sunk through 
50 feet of Upper Lias to a further depth of 50 feet (with 
headings) in the Middle Lias, yielded about 1,000 gallons per day 
at the end of a very dry season. 
In the midland counties from the neighbourhood of Banbury to 
Grantham, the Marlstone is perhaps the most important source 
of water. Nevertheless, in some places the Rock-bed is too thin 
to hold much water. A trial-boring at Castor, near Peterborough, 
carried to a depth of 286 feet, failed to find any large quantity of 
water. J 
* F. Smithe and W. C. Lucy, Proc. Cotteswold Club, vol. x. pp. 202, 204. 
t De Eance, Rep. Brit. Assoc. for 1875, pp. 118, 141 ; Ibid, for 1882, p. 214. 
% J. Addy, Proc. lust. C.E , vol. Ixxiv., p. 147. 
