THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
37 
clay previously described, the river gravel being below. Also 
the fall of the river from Northampton to the sea is so 
small that there is always a tendency to further silt up its 
bed, and so prevent leakage. It was ascertained that there 
was no leakage from the river into the gravel at the Gas 
Works, Northampton, when making excavations for a new 
gasometer ; also none was detected when the large culvert 
was carried across the Cow and Midsummer Meadows to the 
Sewage Works. On the other hand, a well in the river 
gravel, near to the St. James End Ironworks, and only a little 
westward of the Gas Works, evidently tapped the river, for 
the water always stood at the same level in each after a rest. 
There was little or no true alluvium where this well was 
made. One instance where the river was tapped has come 
under my notice. When digging the foundations for some 
new buildings at Nun Mills (Mr. Westley’s) the alluvium was 
pierced, and the river gravel reached, the latter dipping in 
the direction of the old mill at the rate of seven feet in forty. 
Whilst work was going on pumping had to be continued, but 
on a particular Sunday it was noticed that the water in the 
river and the opening made into the gravel stood, as nearly 
as one could judge, at the same level, and as the water in the 
river sank during the day, so did that derived from the gravel. 
Of course both alluvium and gravel may have been much 
disturbed here when making the original mill and mill-head. 
The culvert referred to is only a very short distance away 
from this mill on the other side of the river. Numerous 
wells have been made to obtain water from the river gravel, 
but in no other cases than those mentioned, so far as I know, 
has there been any reason for suspecting that the supply was 
fed by the river. It, therefore, appears pretty certain that no 
considerable draining of the river would take place. 
The supply of water to the proposed dumb-wells would, 
during flood time,, be equal to their utmost capacity for 
receiving it, and during nearly half the year very considerable 
from incipient floods. I have been assured by a gentleman, 
who knows the Nen valley and its adjacent lands well, that 
many streams might with advantage be diverted into shallow 
holes for several months in the year, and some of the dis¬ 
advantages incident to land drainage thus obviated, but a 
consideration of this will come better in Part V. 
IV.—Would the Water be Pure ? 
It will be generally admitted that the water usually 
obtained from the Marlstone, including that supplied to 
Northampton from the same source, is good. There is no 
