726 PROF. J. W. JUDD ON THE NATURE AND RELATIONS OF 
type, was met with; this bed mainly consisted of hard limestone, 
and proved to be 87 ft. 6 in. in thickness, ending at the depth of 
1239 ft. In this stratum a bed of clay, 3 ft. 6 in. thick, was passed 
through at the depth of 1205 ft., and from this Professor Judd pro- 
cured many of the fossils he is about to describe, and which prove 
the bed to belong to the Great Oolite formation. A thin layer of 
Fuller’s Earth was also met with at 1227 ft. 
Two springs of water were struck in this bed at the respective 
depths of 1203 and 1210 ft. from the surface. The water thus 
tapped was found to rise into, and overflow from, the top of a tube 
which was raised 49 ft. above the surface of the ground. The yield 
near the surface of the ground was found to be 17 gallon a minute. 
This water is remarkably soft, being only about two degrees of hard- 
ness by Clark’s scale, and contains 26 grains of chloride of sodium 
per gallon, besides other mineral matter, consisting of carbonate and 
sulphate of soda, with a small quantity of potash salts and carbo- 
nates of lime and magnesia. 
A partial analysis of the oolitic rock at the depth of 1195 ft. from 
the surface showed it to be constituted as follows :— 
Carbonate of Camewyad. assed: Salen ee 87:40 per cent. 
Sand &c. (insoluble in acid) . ... 4:56 
Sulphide of Iron in the form of Py rites. 2-40 35 
At the depth of 1239 ft. beds of a very different character were 
met with, viz. hard red sandstone alternating with beds of variegated 
sandy marl or clay. When the bore-hole had been carried down 
to a depth of 14 ft. into these beds, a further supply of water 
was met with, which rose to the surface and overflowed inte the 
Thames at the rate of 1? gallon a minute. 
After the depth of 1252 ft. 9 in. had been attained the yield 
steadily increased as the boring was deepened. 
The following table shows the quantity of water that overflowed 
into the Thames as the respective depths named were reached :— 
99 
Yield of Water from the Red Sandstone Stratum. 
Depth from Surface. Overflowed Surface at rate of 
fly bon Gallons a minute. 
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