Neither are the States especially interested competent to combine among
themselves for the necessary operations. The work must begin far up the
river; at least as far as Cairo, if not beyond; and must be conducted
upon a consistent general plan throughout the course of the river.
It does not need technical or scientific knowledge to comprehend the
elements of the case if one will give a little time and attention to the
subject, and when a Mississippi River commission has been constituted,
as the existing commission is, of thoroughly able men of different walks
in life, may it not be suggested that their verdict in the case should
be accepted as conclusive, so far as any a priori theory of construction
or control can be considered conclusive?
It should be remembered that upon this board are General Gilmore,
General Comstock, and General Suter, of the United States Engineers;
Professor Henry Mitchell (the most competent authority on the question
of hydrography), of the United States Coast Survey; B. B. Harrod, the
State Engineer of Louisiana; Jas. B. Eads, whose success with the
jetties at New Orleans is a warrant of his competency, and Judge Taylor,
of Indiana.
It would be presumption on the part of any single man, however skilled,
to contest the judgment of such a board as this.
The method of improvement proposed by the commission is at once in
accord with the results of engineering experience and with observations
of nature where meeting our wants. As in nature the growth of trees and
their proneness where undermined to fall across the slope and support
the bank secures at some points a fair depth of channel and some degree
of permanence, so in the project of the engineer the use of timber and
brush and the encouragement of forest growth are the main features. It
is proposed to reduce the width where excessive by brushwood dykes, at
first low, but raised higher and higher as the mud of the river settles
under their shelter, and finally slope them back at the angle upon which
willows will grow freely. In this work there are many details connected
with the forms of these shelter dykes, their arrangements so as to
present a series of settling basins, etc., a description of which would
only complicate the conception. Through the larger part of the river
works of contraction will not be required, but nearly all the banks on
the concave side of the beds must be held against the wear of the
stream, and much of the opposite banks defended at critical points. The
works having in view this conservative object may be generally
designated works of revetment; and these also will be largely of
brushwood, woven in continuous carpets, or twined into wire-netting.
This veneering process has been successfully employed on the Missouri
River; and in some cases they have so covered themselves with sediments,
and have become so overgrown with willows, that they may be regarded as
permanent.
