176 
THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
reservoirs for surplus water. I believe they now act in much 
the same way as the chalk, i.e., absorb large quantities of 
water and slowly deliver it to the water-bearing bed at their 
base, and thus tend to equalise the flow throughout the year. 
If the lower water-bearing bed were more frequently used, 
and the water pumped from it at points situated some 
distance from its outcrop, there is little doubt that the sandy 
beds of the “ Margaritatus ” Zone would absorb and allow to 
pass through them much more water than they do now. 
At only one place —Dodford— have I seen water actually 
flow from these soft beds, and there it might have been from 
a fissure communicating with the lower spring, as it was 
most certainly within a few feet of the latter. The general 
dryness of Middle Lias lands, of these beds as seen in a 
section, and the readiness with which a specimen will 
absorb water, combined with the fact that nearlv all the 
fossils found in them are casts only, show that water has a 
fairly ready passage through them. Now, although the 
success of the scheme for water supply that I am discussing 
does not depend upon these beds retaining the characters 
they have in the western parts of the county as far as 
Northampton, nor, indeed, upon their existence there, still 
a demonstration of their presence, and of the lower spring, 
so far eastward, would favour any project for the utilisation 
of the Middle Lias as a reservoir for surplus water. 
On the first occasion when this scheme was presented to 
the Water Committee of the Town Council of Northampton, 
I spoke of the sandy micaceous clays and the second spring 
as existing at Northampton, but the existence of either was 
denied, I presume from a consideration of the results 
obtained at the Spinney Well. Considering that I put a 
different interpretation on the results of this boring, I also 
retained my opinion on the two points referred to above. 
With regard to the porous beds of the “ Margaritatus ” 
Zone I may have been partly wrong; that is, they may be 
less sandy, and consequently less porous under Northampton 
than further westward, as they are thinner, but this is not 
certain ; what little evidence there is will be given presently. 
So far as these beds can be traced by superficial sections, 
they vary very little. At Staverton, Badby, Newnham, and 
on the north side of the great Nen fault, near to Weedon (new 
railway cutting), they have nearly the same characters. The 
evidence as to the lower spring has accumulated until it is 
quite conclusive. It must be borne in mind, that in making 
wells in the Middle Lias, water is, practically, always found 
in the Rock-bed, and until recent years the water so found 
