weight of authority is in
favor of four-foot drains. In this country, a less depth has thus far,
in general, been adopted in practice, but it is believed that this has
been because a greater depth has not been tried. It is understood, that
the most successful drainers in the State of New York, have been
satisfied with three-foot drains, not, as it is believed, because there
is any instance on record, in this country, of the failure of four-foot
drains, but because the effect of more shallow drains has been so
satisfactory, that it has been thought a useless expense to go deeper.
To Mr. Johnston and to Mr. Delafield, of Seneca County, the country is
greatly indebted for their enterprise and leadership in the matter of
drainage. Mr. Johnston gives it as his opinion, that "three feet is deep
enough, if the bottom is hard enough to lay tiles on; if not, go
deeper."

Without intimating that any different mode of drainage than that
adopted, would have been better on Mr. Johnston's farm, we should be
unwilling to surrender, even to the opinion of Mr. Johnston and his
friends, our conviction that, in general, three-foot drains are too
shallow. Mr. Johnston expressly disclaims any experience in draining a
proper clay soil. In the _Country Gentleman_, of June 10th, 1848, he
says:

"In a subsoil that is impervious to water, either by being a red
clay, blue clay, or hard-pan, within a foot of the surface, I would
recommend farmers to feel their way very cautiously in draining. If
tiles and labor were as low here as in Great Britain, we could
afford to make drains sixteen feet apart in such land, and then, by
loosening the soil, say twenty inches deep, by the subsoil plow, I
think such land might be made perfectly dry; but I don't think the
time is yet come, considering the cost of tiles and labor, to
undertake such an outlay; but still it might pay _in the end_. I
have found only a little of red clay subsoil in draining my farm. I
never had any blue clay on my farm, or hard-pan, to trouble me; but
I can readily perceive that it must be equally bad to drain as the
tenacious red clay. If I were going to purchase another farm, I
would look a great deal more to the subsoil than the surface soil.
If the subsoil is right, the surface soil, I think, cannot be
wrong."

In the same paper, under date of July 8th, Mr. Johnston says, "The only
experience I have