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NEW YORK STATE MUSEUM 



out has been amply repaid. Wherefore, in grateful recognition 

 of the eminent services rendered by Colonel Tulla, the original 

 promoter of the scheme, a statue has been erected in his honor 

 at Maxau on the banks of the river. 



In one respect only has the regulation of the river not ful- 

 filled the expectations of its promoters, viz. the extensive sand- 

 banks formed at the confluence of its tributaries have rendered 

 inter-communication with them both difficult and dangerous, 

 because these feeders to the main stream enter it across bars 

 little more than 0.60 or 1.50 metre below low-water level. 



Had the hydraulic engineers in 1817 correctly determined 

 the minimum discharge of the Rhine, and at the same time 

 anticipated a probable decrease of the same, they would have 

 diminished the waterway, and thereby considerably reduced the 

 deposit formation of such sandbanks so that the channels of 

 communication (between the Rhine and its tributaries would 

 have remained more open to navigation. 



In addition to the foregoing general principles, applying more 

 particularly to the non-tidal portion of rivers, rivers emptying into 

 the sea, or into an arm of the sea, may require special treatment, 

 and while, aside from the Hudson river, there are few such in 

 this State, and although the improvement of this stream has been 

 assumed by the Federal government, nevertheless it is proper to 

 briefly consider the general principles governing such an im- 

 provement. 



Generally speaking, the regulation of rivers flowing into the 

 sea is more costly than that hitherto treated of, because the vol- 

 ume of water is greater and the yielding nature of the silt forming 

 the beds and banks, together with the violence of the stream and 

 force of the waves, render it necessary that whatever the form of 

 protection, it shall have solid foundations and be executed in the 

 most substantial manner. 



The works necessary for the perfect regulation of such a river 

 consist of : 



1) Rendering the course as nearly straight as possible in order 

 to increase the fall. 



2) Inclosing the river at or near ils outfall by moans of dykes 

 or jetties, and continuing the same beyond the bar and far enough 

 out to sea to enable the current to carry the sand and mud away, 

 thus preventing the formation of a bar at the mouth. 



