38 
THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
the water level sinks air follows, which latter is again largely 
expelled and partly absorbed by the next influx, and so a 
rather good aeration is the result. 
Drift Gravel Springs.— A considerable portion of 
Northamptonshire is covered by Boulder clay or gravel 
deposited during the Glacial period, and the gravel furnishes 
very numerous springs of pretty good water, where it rests 
upon impervious beds. Besides this there are some rather 
extensive deposits of a fine sand or gravel, differing 
considerably from the ordinary drift gravel, though probably 
of the same age. These latter deposits appear to be very 
local, and to consist of redeposited Northampton sand, as 
none of the flints and pebbles, &c., so enormously abundant 
in the ordinary drift are present, whereas fragments of 
ironstone are very common. There is a tolerably extensive 
deposit of this form of drift within a few miles of Northampton, 
and during the discussion on the water supply of the town, 
Mr. Westley, of Kislingbury, several times urged the adoption 
of it a-s a source of water. The particulars which Mr. 
Westley gave were about as below:—“ Catchment area about 
12,000 acres, extending for about five miles through the 
parishes of Courteenliall, Collingtree, Milton, Botliersthorpe, 
Kislingbury, and Bugbrook, with a width varying from 
twenty to fifty chains (say an average of twenty-five chains), 
and a thickness of twenty to forty feet of sand, from which 
good and never-failing springs issue. Assuming fifteen inches 
of rainfall absorbed, it would yield a yearly supply of 
408,000,000 gallons, or rather more than 1,000,000 gallons 
per day.” This scheme was not entertained, and even 
supposing the amount of water estimated by Mr. Westley 
could have been realised, it is not a quantity adequate for 
the supply of Northampton; and being very superficial, it 
would be open to some of the objections urged against the 
River gravel springs. It is so situated that water could not 
be stored in it to any great extent, and so in times of drought 
it might fail altogether, I do, however, think that a supply 
ol water like this might be made useful, and the particular 
feature of the scheme I have to propose is that such partial 
supplies could be used at comparatively little expense. 
The Great Oolite Springs.— Most of the high lands 
around Northampton — Kingstliorpe, Dallington, Duston, 
Wooton, B1 is worth, Moulton Park, &c.—are capped by 
limestone ot Great Oolite age, a rock which allows water 
to percolate through it; and alternating with the limestone 
are beds ol clay — sometimes two, at other times three—which, 
owing to the resistance they offer to the passage of water 
