THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
281 
lias been made of the fact that no water was obtained at the 
Spinney Well just outside Northampton, at a point less than 
a mile from a well in the same formation yielding at the same 
time some hundreds of thousands of gallons daily. In this 
well, of which a description has been given, headings were 
driven 352 feet to the north-west, and 141 feet to the north¬ 
east, but no flow of water could be obtained. The cause of 
failure was, in the first instance, attributed to the existence 
of an anticlinal curve, and afterwards to the closeness of the 
rock. 
I have all along believed that an anticlinal curve exists 
in the valley where the Spinney Well was made, and that 
the general lowering of the water-level in the Marlstone 
had thus left the Bock-bed dry. The proofs I am now able 
to offer are quite conclusive as to the adequacy of this cause, 
and I am not aware of any reason for the alternative 
explanation. 
Speaking generally for Northamptonshire, I should say it 
is a mistake to sink for water in a valley, now that the general 
water-level is so low, because it often happens that valleys 
coincide with, and, indeed, had their origin in, anticlines of 
the strata. It is really very common to find superficial beds 
dipping into the lulls, and consequently forming under them 
synclinal curves, with corresponding anticlinals in the valleys. 
At three points at least on the new railway line between 
Weedon and Daventry (about four miles) this may be seen 
at the present time (1887). 
When a curve is produced.in a set of beds by upheaval at 
one part, or along one line, it is clear that the beds forming 
the curve will occupy a larger space than the same beds did 
whilst forming a plane. Those forming the lower part of 
the convex curve may preserve their continuity by re-adjusting 
themselves in obedience to the pressure above them, but the 
upper ones will crack, and that most deeply at the highest 
point of the curve. The exposed edges of the strata at the 
cracks being much more easily denuded than the surfaces of 
the same strata, we have here the initiative for the formation 
of a valley, under which, of course, the lower beds will form 
an anticline. 
1 not only think that many of our valleys have been 
started in this manner, but that “ faults ” have also been 
produced by shearing along the line of weakness produced by 
these cracks. 
Returning to the Spinney Well :—We find that it is 
situated at small, and nearly equal, distances to the south-east 
