42 
On Thorough- Draining. 
This, as soon as the wood or straw begins to decay, the perpendicular 
pressure of tlie water will cause to fall in ; whereas, should the stiff soil 
taken out by tlie spade be replaced, with the view of rendering the drains 
more secure, it will soon become so closely wedged into the narrow space 
from whence it was previously taken, that though the drain remains open 
at the bottom the water will be unable to find its way down to it. 
Added to this, such drains are liable to be choked by the thin silt 
driven by the autumn rains into the fissures caused by the drought of 
summer ; and water is thus admitted into a sub-soil from which, by good 
surface-drainage, it could be almost entirely excluded. 
This latter remark would, I conceive, apply equally to the use of tiles 
in such land, as the silt driven into the fissures would effectually obstruct 
the drains, and throw the water out upon the surface. 
The only materials capable of being used with real advantage on sucli 
soils are, I should imagine, those to which I have previously referred, 
viz., small stones, shingle, or shell ; but these can usually only be im- 
ported from a distance, and at considerable expense, so that the conse- 
quent cost renders it almost hopeless that such a mode could ever be 
generally adopted. 
I have entered more at length than perhaps is necessary into this sub- 
ject; but the conviction, that such land would be much improved if it 
were possible to drain it effectually — that it would be less subject to the 
destructive injuries of wet seasons — that it would be more easily worked 
at all times — that the ploughings of autumn and wheat-seed time would 
be less hazardous and laborious — that the tillage of spring would be more 
certain and earlier — makes me feel deeply interested in the subject, and 
anxious to see such a system introduced as would bring about the de- 
sired result. Never having been in Scotland, I cannot speak from my 
own observation, but from all that I have read of the draining of the 
heavy lands of that country, I have never been able to conceive that the 
heavy lands to which effectual drainage has there been applied are equal 
in stiffness, in tenacity, in stubbornness, to our own ; and I have always 
judged from such incidental observations, as " the possibility of plough- 
ing at all times with two horses," &c., that I am in some degree justified 
in my conclusion. Besides this, I was struck a short time since by an 
observation of Mr. Hyde Greg, in his recent pamphlet on the subject, 
who, after extolling the practice as applicable, to all land, cannot at last 
avoid the admission, that the land to which he has referred can hardly 
be so heavy as some of the heavy land of England. 
Wherever land is not uniformly sound, but intersected by veins of 
looser soil, there drainage must of necessity be applied to let out the 
water which such veins have admitted ; and on the tenacious loamy 
clays where this is the case (until some better method is introduced), 
drainage by shallow ditches, filled with wood and straw, and frequently 
renewed, is, perhaps, the best method that can be adopted. 
In clay soils the drains are seldom more than a rod or a rod and a half 
apart; in gravelly soils, where the water will draw more readily through 
the subsoil, they may be further distant, but of greater depth, so as not 
only to carry off the water rising from the springs below, but also to give 
that from the surface a readier inclination to the drains. 
