on for laying them out properly.

Again, experience gives great facility in judging of the underground
flow of water, of the permeability of soil, of the probability of
finding ledges or other rock formation, and many other particulars which
might not suggest themselves to a novice in the business.

The laying out of drains is important, not only with reference to the
work in hand, but to additional work to be executed in future on
adjoining land, so that the whole may be eventually brought into one
cheap and efficient system with the smallest effective number of drains,
both minors and mains, and the fewest outlets possible; with such wells,
or other facilities for inspection, as may be necessary.

In the English tables of the cost of drainage by the Drainage Companies,
an estimate of $1.25 per acre is usually put down for "superintendence,"
which includes the engineering and the supervision of the whole process
of opening, laying and filling, securing outfalls, and every other
process till the work is completed. The general estimate of the cost of
drainage is about $25.00 per acre, and this item of $1.25 is but a small
per centage on that amount. The point has been dwelt upon here, more for
the purpose of impressing upon land-owners, the importance of employing
competent skill in the laying out of their drainage works, than because
the expense thus incurred, forms any considerable item of the cost of
the whole work.

2. _Excavation and Filling._ The principal expense of drainage is
incurred in the excavation of the ditch, whether it be for tiles or for
stones. The labor of excavation depends much upon the nature of the soil
to be moved.

"Draining on a sound clay," says the writer of a prize essay,
"free from stones, may be executed at a cheaper rate per rod, in
length, than on almost any other kind of soil, as, from the
firmness of the clay, the work may be done with narrow spades, and
but a small quantity of soil requires to be removed. The draining
of wet sands or grounds, or clays in which veins of sand abound, is
more expensive than on sound clays, because a broader spade has to
be used, and consequently a larger amount of soil removed; and
draining stony or rocky soils is still more expensive, because the
pick has to be used. This adds considerably to the expense."

Great stress is laid, by all experienced persons, upon using narrow
spades, and opening ditc