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ings of the five cross-sections of the river established during the first survey, with three additional cross-sections extending to Fort Washington.

Under the act of July 5, 1884, the survey of the west bank of the river in this section was extended to Weehawken, and soundings duplicated at all the previous cross-sections.

These several surveys have been directed by Congress with the view of determining the nature of the improvements which it may be practicable to undertake in order to deepen the water on the approach to the wharves on the west side of the river.

It bas been stated in previous reports on this subject that the deposits which occasion the obstruction alongside the wharves on the right bank of the Hudson, below Castle Point, are the result of uatural causes, i.e., the set of the currents toward the east bank, occupied by New York City, due to the sinuosity of the river above, and the vatural shore projections from the west side of which Castle Point is a conspicuous ex ample, assisted by artificial projections close to and below Castle Point on the same side. These may be regarded as permanent causes tending to maintain shoal water on the west side; and nothing but their total removal, now impracticable, will bring about any but a temporary change, so long as the dock lines on the east side are judiciously established..

I take occasion to say right here that the two banks of the river are ; kept in view when considering the subject of pier-head lines.

A disregard of the mutual relations of the two systems of lines mas; after construction, surprise the builders by the results obtained.

A pier-bead line, for instance, which would allow long piers to be built out from the east bank at and above Fourteenth street, New York City, might benefit adjacent wbarves by giving increased depth there, but the effect of such constructions would be to deflect the currents to the opposite bank, tending to reverse existing conditions of velocities and depths on the two shores below Fourteenth street; that is, to deepen the bed on the west shore and to shoal that on the east.

As the wharves on the west shore are located upon a convex bank, where languid currents exist, and where deposits are made by local sewers, and by shipping occupying berths in the slips, it is natural to expect that there would be, as a result of these conditions, a con tinuous and progressive shoaling of the water near the wharves and in the slips.

The currents have insufficient velocities to produce any scour, so that all deposits made upon the bed must be removed, periodically, by art ficial means. The only expedient measure of relief, then, is by dredg ing or by establishing the pier line closer to the deep water channel

. The frequency with which dredging is required here and the cost attending this kind of relief led me, in my report of February 16, 1884. to disapprove the further expenditure of money for dredging, and to recommend that the pier-line be located within and near the 25-foot curve of the adjacent shore, believing then, as I now believe, that the establishment of such a line will not be injurious to tbe regimen or tidal propagation of the river. An examination of the soundings last taken along the cross-sections at the several permanent stations, ex ? hibited upon the accompaning chart, shows that no material change has taken place during the year in the depths at Castle Point or at Wee. hawken as the result of the shore improvements constructed at the latter point by the railroad authorities.

In my judgment the pier-head line within the 25.foot curve, which has been recommended for that part of the west shore lying below

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