On Draining. 
257 
cost of drainage per acre to vary from 2/. to even 5/. per acre, 
according to circumstances. 
The following is an instance of the utility, the necessity I 
ought to say, of well examining soil — of ascertaining, in fact, what 
we have to deal with before commencing drainage. I was in- 
vited in February last to visit the property of the Duke of 
Wellington, at Stratfield-Saye. "I found a particular grass-field, 
which it was desirable to drain, very wet, and it was thought that 
no drainage deeper than about 2 feet would have any effect upon 
it, as drains in other parts which had been made 3 feet 6 inches 
deep had not effected much more good than the shallower ones. 
It was also thought that the mass of clay beneath would be found 
almost impervious to water, as cracks had only opened in hot 
seasons to about 15 inches deep. However we had the turf and 
mould borne off a space of about 5 feet square and 22 inches 
deep, when a bed of yellow plastic clay appeared. Into this bed, 
which was soft and easily worked by the hand, a hole was sunk. 
But a very slight quantity of water oozed into the hole until we 
reached about 4 feet 3 inches, when the hole rapidly filled with 
water. It was still clay, but evidently of a more porous nature, 
and there a mass of free water resided. It was apparent that the 
cause of the upper clay and surface soil being so wet in defiance 
of the shallow drains, was now discovered, for as the upper clay 
reposed on what, relatively, may be called a pillow of water 
below, the capillary force, always in action, continually sucked up 
this water, and supplied the incumbent soil with a perpetual ex- 
cess of fluid. The shallow drains might have done their duty in 
removing the water of rain — the surface water — but they could in 
nowise affect the liberation of the bottom water. An experimental 
drain was then made, 5 feet in depth and 350 yards long, laid 
with ll inch bore pipes. Clay was puddled in over this line of 
pipes up to 2 feet 6 inches from the surface, and another line of 
similar pipes was then laid ; so that we had a shallow and deep 
drain in the same trench, the object being to measure the relative 
discharges of water from each, and the lower drain was puddled 
over to prevent as much as possible the top water from mixing 
with the bottom. The result was that the bottom drain dis- 
charged, from the commencement, a stream averaging one gallon 
per minute during seventy-six days, being equal to nearly 5 tons 
every twenty-four hours. The run then rapidly diminished, and 
speedily came to drop only. A second 5-feet-deep drain had 
been made 36 feet distant, so as to insulate a space of land on 
one side of the experimental drain, and it will be found that, 
taking the length of 350 yards witli a breadth of 12 yards as 
affording water to the bottom drain (G yards on each side of it), 
no less than an area of 4200 square yards of water, 5.^ inches 
VOL. VII. s 
