he outflow of all
water above its level. It would be folly to raise water by expensive
means, which can be removed, even periodically, by natural drainage.

When pumps are used, their discharge pipes should pass through the
embankment, and deliver the water at low-water mark, so that the engine
may have to operate only against the actual height of the tide water. If
it delivered above high-water mark, it would work, even at low tide,
against a constant head, equal to that of the highest tides.

CHAPTER X. - MALARIAL DISEASES.

So far as remote agricultural districts are concerned, it is not probable
that the mere question of health would induce the undertaking of costly
drainage operations, although this consideration may operate, in
connection with the need for an improved condition of soil, as a strong
argument in its favor. As a rule, "the chills" are accepted by farmers,
especially at the West, as one of the slight inconveniences attending
their residence on rich lands; and it is not proposed, in this work, to
urge the evils of this terrible disease, and of "sun pain," or "day
neuralgia," as a reason for draining the immense prairies over which they
prevail. The diseases exist,--to the incalculable detriment of the
people,--and thorough draining would remove them, and would doubtless bring
a large average return on the investment;--but the question is, after all,
one of capital; and the cost of such draining as would remove
fever-and-ague from the bottom lands and prairies of the West, and from
the infected agricultural districts at the East, would be more than the
agricultural capital of those districts could spare for the purpose.

In the vicinity of cities and towns, however, where more wealth has
accumulated, and where the number of persons subjected to the malarial
influence is greater, there can be no question as to the propriety of
draining, even if nothing but improved health be the object.

Then again, there are immense tracts near the large cities of this country
which would be most desirable for residence, were it not that their
occupancy, except with certain constant precautions, implies almost
inevitable suffering from fever-and-ague, or neuralgia.

Very few neighborhoods within thirty miles of the city of New York are
entirely free from these scourges, whose influence has greatly retarded
their occupation by those who are seeking country homes; while many, who
have braved the dangers of