e seems well established, that depth will compensate
for width; or, in other words, that the deeper the drain, the farther it
will draw. This principle, generally correct, is questioned when applied
to peculiar clays only. As to them, all that is claimed is, that it is
more economical to make the drains but three feet, because they must,
even if deep, be near together--nobody doubting, that if four feet deep
or more, and near enough, they will drain the land.

In speaking of _clay_ soil, it should always be borne in mind, that clay
is merely a relative term in agriculture. "A clay in Scotland," says Mr.
Pusey, "would be a loam in the South of England." Professor Mapes, of
our own country, in the _Working Farmer_, says, "We are convinced, that,
with thorough subsoil plowing, no clay soil exists in this country which
might not be underdrained to a depth of four feet with advantage."

There can be no doubt, that, with four-foot drains at proper distances,
all soils, except some peculiar clays, may be drained, even without
reference to the changes produced in the mechanical structure of soil by
the operation. There is no doubt, however, that all soils are, by the
admission of air, which must always take the place of the water drawn
out, and by the percolation of water through them, rendered gradually
more porous. Added to this, the subsoil plow, which will be the
follower of drainage, will break up the soil to considerable depth, and
thus make it more permeable to moisture. But there is still another and
more effective aid which Nature affords to the land-drainer, upon what
might be otherwise impracticable clays.

This topic deserves a careful and distinct consideration, which it will
receive under the title of "Drainage of Stiff Clays."

In discussing the subject of the depth of drains, we are not unmindful
of the fact that, in this country, the leaders in the drainage movement,
especially Messrs. Delafield, Yeomans, and Johnston, of New York, have
achieved their truly striking results, by the use of tiles laid at from
two and a half to three feet depth. On the "Premium Farm" of R. J. Swan,
of Rose Hill, near Geneva, it is stated that there are sixty-one miles
of under-drains, laid from two and a half to three feet deep. That these
lands thus drained have been changed in their character, from cold, wet,
and unproductive wastes, in many cases, to fertile and productive fields
of corn and wheat, sufficiently appears. Indee