424 
Oil Drain! 
5. Tliat the drain shall be perfectly straight, with a regular 
fall from one end to the other. 
6. That too much earth be not moved in cutting the drain, it 
being considered that no more earth should be moved than is 
necessary lor the drainer to perform his work with facility. 
7. That the whole of the earth be again put into the turf-drain, 
and in the tile-drain as nearly as possible. 
'8. That the time for making a drain 22 yards, complete in 
every respect, shall not exceed five hours. 
The width at which the wedge or turf-drainers lay out their work 
at the surface varies from 6^ to 8;V inches, the tile-drainers from 
8 to 9 inches. The men, with these widths at the surface, cut the 
two sides of the drain with the same inclination from the top to the 
bottom, and so straight and smooth that it is scarcely possible for 
the eye to detect the slightest variation ; and the bottom of the 
wedge or turf-drains not more than one inch wide, with a uniform 
fall. The wedge is placed and trodden firmly down within 5 or 6 
inches of the bottom, and the clay put immediately over it, so 
that the waste turf and soil are again laid on the surface.* I have 
always noticed that the water runs into the main drain before the 
work is completed ; but as the pure clay is put upon the wedge, 
and beaten down more closely than before it was dug out, the 
water cannot, for a short time, pass through the clay above the 
wedge into the conduit, but, as I have before shown, horizontally 
with the bottom, or through the sides. 
Having proved, from practical observation, that the perfect 
drainage of tenacious clay soils, by any mode oi JiUiiif/-iii above 
the conduit, cannot be eflectual, I shall further state why the 
water in land not drained, and where the expansion of the subsoil 
during the winter has taken place, filters so freely into the drain 
on a level with the bottom. Land which lies wet from surface- 
water during the winter, at the middle or end of March will, on 
tlie surface, by evaporation, generally be dry, but below the sur- 
iace it will contain water. The fissures, &c., being ahnost closed 
bv the expansion of the subsoil during the winter, the water, in 
descending from the surface, becomes perfectly clear ; and clear 
water will filter through almost any medium, and through any clay 
subsoil, to the depth the same has been contracted b}' the atmos- 
])licre in dry seasons. Where fissures, worm-bores, &c., are 
(mce formed in a retentive clay soil, they cannot be altogether 
obstructed unless the soil were worked together by artificial 
means. Most parties are acquainted with the difficulty tliat is often 
* If the spring is advanced, it is recommended not to brine: the waste 
luri' quite 1o the surface, but (o cover it with about one inch of light or top 
^oil. The turf will quickly grow through, and not perisii, as it is apt to do 
when laid on the surface in dry weather. 
