and fifty feet
apart, in an open soil, they seem amply sufficient to relieve the ground
of all surplus water from rain, in a very few days. Most of them have
never ceased to run every day in the year, but as they are carried up
into an undrained plain, they probably convey much more water than falls
upon the land in which they lie.

So far as our own observation goes, their flow increases almost as soon
as rain begins to fall, and subsides, after it ceases, about as soon as
the water in the little river into which they lead, sinks back into its
ordinary channel, the freshet in the drains and in the stream being
nearly simultaneous. Probably, two-inch pipes, at fifty feet distances,
will carry off, with all desirable rapidity, any quantity of water that
will ever fall, if the soil be such that the water can pass through it
to the distance necessary to find the drains; but it is equally probable
that, in a compact clay soil, fifty feet distance is quite too great for
sufficiently rapid drainage, because the water cannot get to the drains
with sufficient rapidity.

DISTANCES DEPEND UPON THE COMPARATIVE PRICES OF LABOR AND TILES.

The fact, that the last foot of a four-foot drain costs as much labor as
the first three feet, is shown in another chapter, and the deeper we go,
the greater the comparative cost of the labor. With tiles at $10 per
thousand, the cost of opening and filling a four-foot ditch is, in,
round numbers, by the rod, equal to twice the cost of the tiles. In
porous soils, therefore, where depth may be made to compensate for
greater distance, it is always a matter for careful estimate, whether we
shall practice true economy by laying the tiles at great depths, or at
the smallest depth at which they will be safe from frost and the subsoil
plow, and at shorter distances. The rule is manifest that, where labor
is cheap and tiles are dear, it is true economy to dig deep and lay few
tiles; and, where tiles are cheap and labor is dear, it is economy to
make the number of drains, if possible, compensate for less depth.

DISTANCES DEPEND UPON SYSTEM.

While we would not lay down an arbitrary arrangement for any farm,
except upon a particular examination, and while we would by no means
advocate what has been called the gridiron system--of drains everywhere
at equal depths and distances--yet some system is absolutely essential,
in any operation that approaches to thorough drainage.

If it be only desired to