Page:Popular Science Monthly Volume 29.djvu/858

838 dikes of a height not to exceed that of high water. 2. The dredging of the loose and movable material from the bottom. 3. The direction of the channel as defined by the dikes to be as straight as possible, and the changes of direction to be made by easy curves. 4. A gradual increase in width of the channel from Troy to New Baltimore as being more favorable for a higher rise of tides. 5. The closing of the side-passes generally, but leaving an opening for the influx of the flood. 6. Revetting of island-shores and river-banks where exposed to abrasion. 7. The limits of the encroachment on the river-bed to be defined and enforced by proper authority. 8. Deposition of dredged material beyond the action of currents. 9. The abandonment of the idea of obtaining a scouring effect by the height of the dikes. In fine, dikes are advocated with the view to give direction to the freshet, flood, and ebb currents; to prevent cross-currents, and consequent filling up of the channel; to lead and bring up a greater volume of tidal waters; and, consistently with these objects, the dikes should be constructed as low as possible, in order to allow the freshet-water to spread. Estimates were made for the work, to be completed in five years; it is still not complete, nor has the work been carried on without opposition from steamboat-men and parties judging that they were to be pecuniarily injured. Near Coeyman's this opposition was very strong, but, since construction, the opponents have acknowledged that their apprehensions of inconvenient results were erroneous, and have been satisfied with General Newton's engineering.

Gradually with the extension of navigation improvements General Newton reported on all the channels and harbors in the vicinity of New York, from Lake Champlain on the north to the Raritan and Arthur's Kill on the south, superintending constructions where appropriations had been granted. He was also one of the commissioners for the improvement of the harbor of Montreal.

But the great construction with which General Newton's name is identified is the improvement of the Hell-Gate Channel, the important water-way between Long Island Sound and East River, of New York city. His first examinations for the improvement of Hell-Gate, and the report, with cost of constructions, were made to Congress February 12, 1867. The first propositions were merely tentative. The plan recommended for the removal of reefs was by holes drilled from a platform above water. A contract was given to Maillefert & Co. to remove Pot Rock and some other like obstructions by depositing explosives on the surface of the rock and firing them. This was found to be very expensive and tedious, and the contractor who undertook to drill from above the water was not successful.

In June, 1869, General Newton submitted a report for the removal of Hallet's Point by sinking shafts on the shore-side to a sufficient depth, and from the bottom of these shafts running galleries under the rock to be removed, the opening below being calculated to be