a head of
water may be obtained to supply the requisite power, the cost need not be
considerable after the first outlay; but, even though steam-power should
be requisite, in connection with the admirable Pumping machinery of our
day, Irrigation would pay liberally in thousands of cases. Such easily
parched levels as those of New-Jersey and Long Island would yield at least
double their present product if thoroughly irrigated from the turbid
streams and marshy ponds in their vicinity. Water itself is of course
essential to the growth of every plant, but the benefits of Irrigation
reach far beyond this. Of the fertilizing substances so laboriously and
necessarily applied to cultivating lands, at least three times as great
a proportion is carried off in running water as is absorbed and exhausted
by the crops grown by their aid; so that if Irrigation simply returned to
the land as much fertility as the rains carry off, it would, with decent
husbandry, increase in productiveness from year to year. The valley of
the Nile is one example among many of what Irrigation, especially from
rivers at their highest stage, will do for the soil, in defiance of the
most ignorant, improvident and unskillful cultivation. Such streams as the
Raritan, the Passaic and most of the New Jersey rivers, annually squander
upon the ocean an amount of fertilizing matter adequate to the comfortable
subsistence of thousands. By calculation, association, science, labor,
most of this may be saved. One hundred thousand of the poor immigrants
annually arriving on our shores ought to be employed for years, in
New-Jersey alone, in the construction of dams, canals, &c., adequate to
the complete irrigation of all the level or moderately sloping lands in
that State. Farms are cheaper there to-day than in Iowa for purchasers
who can pay for and know how to use them. Long Island can be rendered
eminently fertile and productive by systematic and thorough Irrigation;
otherwise I doubt that it ever will be.

Much of Lombardy slopes very considerably toward the Po, so that the
water in the larger or distributing canals is often used to run mills
and supply other mechanical power. It might be used also for
Manufacturing if Manufactures existed here, and nearly every farmer
might have a horse-power or so at command for domestic uses if he chose.
We passed yesterday the completely dry beds of what seemed to be small
rivers, their water having been entirely drawn away into