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On the Drainage of Land. 
No. 1 will drain the whole width, and keep the water 18 inches 
from the surface, the fall of the water in passing through the soil 
being 1 in 33. 1 drained a piece this winter at about this power 
of drawing, which I proved by digging a hole midway between 
the drains. No. 2 would require one more drain at A, or 11 yards 
apart. No. 3 will want two more at A and B, or 7^ yards apart ; 
and No. 4 three more, or at A, B, and C, or 5^ yards apart. 
This will drain any soil ; the internal fall required by the latter, if 
the water is kept only 1 foot below the surface, will be about 1 in 
6, which is very great, perhaps greater than any land has. It may 
be asked how and when is the proper time to judge of the above ; 
perhaps the easiest way to find it out will be, after you have made 
two drains parallel with each other, at the distance which you 
think the land requires, to dig a hole midway between them of 
the same depth with the drains, and so ascertain the height at 
which the water stands above the drains in the rainy season, 
proper time being allowed for the water to go off, according to 
the tenacity of the soil ; say two or three days after rain in Febru- 
ary, when the land is generally as wet as in any month. It will 
also show itself before land is drained, if the land has been 
ploughed in ridges. In fields where the ridges are not very high, 
I have seen the water stand on the top of them ; and where they 
are high, they are wet some way up from the furrow, according to 
their steepness or the tenacity of the soil. 
As you cannot fix a rule for both depth and frequency to suit 
all soils, I should say that, with few exceptions, the depth should 
be 30 inches, and from 22 to b\ yards' distance ; a few instances 
wider, but few requiring them so near as 5^ yards. I drained a 
piece of poor wet clay-land, which I was told would not draw a 
yard ; but I found the drains act at 7 or 8 yards' interval, or 4 
yards on each side of the drain. Though deeper draining would 
require fewer drains, it is not always advisable to cut deeper, as 
sometimes it is very difficult to get a proper outlet for the water 
without extra depth of ditches, which cannot always be obtained. 
The Materials I have used are tiles, stone, and clay. For 
land having little fall, hollow drains are best, because there is a 
better passage for the water ; therefore on such land tiles are 
best, and on clay-soils there should always be some flats put under 
them ; some tiles are made with feet, thus, .r\ ; but that I should 
not trust to on clay-land, and on rubble or gravel it is unnecessary. 
Besides, flats or chips of slate, about the size of one's hand, for 
the ends of both tiles to rest on, leave the tile hollow from the 
ground, Which will allow the water to enter better than if it rests 
on the clay, in which, even if the tile does not sink deep, it will 
in time become firmly imbedded, and the entrance of the water 
be thereby retarded ; for this reason, I should say, such pieces 
