THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
233 
Well could rise 133 feet above sea-level; indeed, bearing in 
mind the general dip and strike of the Mesozoic beds, and 
the situation of these two wells respectively, one would expect 
a slightly lower level for the water at the Spinney Well. 
At any rate it is evident that the water must have risen quite 
or nearly up to the Middle Lias Rock-bed, for if we add to 
the depth of the Rock-bed at the Spinney Well its thickness 
of 7 feet 6 inches, making altogether 178| feet from the surface, 
it will be evident that its base is 99J feet above sea-level, and 
so, if the water rose as high as at Kingsthorpe shaft (104 feet 
above sea-level), the Rock-bed would be covered to the extent 
of 4J feet, and the salt water would run away into it. 
Kingsthorpe Shaft is situated a little over a mile from 
the Spinney Well, but is within sight of it; it was made 
50 years ago with the idea of finding coal. According to the 
account left of the work, it has a depth of 967 feet, the 
Marlstone was reached at 210 feet, and yielded a supply of 
water equal to 36,000 gallons per hour. The shaft is now 
filled with salt water to within 270 feet of the top—that is, 
60 feet below the recorded position of the Marlstone Rock-bed. 
No water now flows into it from any point above the salt¬ 
water level. 
I should not think of calling in question the accuracy of 
any of the figures given above but for the fact, well known, 
that no detailed section of the shaft was taken at the time 
it was being made, hence errors of depth might easily be 
made. 
Shortly after the Spinney Well was abandoned, the Kings- 
tliorpe shaft was opened to see if the Marlstone there continued 
to yield water. A small quantity of water was found to be 
making its way into the pit near the surface of the ground, 
but when that was stopped there was no flow anywhere. The 
lining of the shaft was broken through and the rock tapped, at 
short intervals, from the surface of the water to a considerable 
distance above it, but no water obtained. In April, 1881, I 
made a slight investigation of the pit, at the request of Lady 
Robinson, on whose land it is situated. A workman broke 
the lining of the shaft, or utilised the openings already made, 
and brought up small specimens of the rock from numerous 
depths between 150 feet and the surface of the water. The 
rock in every case was clay, and although, in the absence of 
fossils, one might be easily misled, my impression was that it 
was all Upper Lias, and that the Middle Lias Rock-bed was 
below the water level, and so at least 60 feet lower than its 
supposed position. 
