now proposed will "obstruct, impair, or injuriously modify the navigation of the river." It will be seen from the drawings that one of these plans consists of two whole spans and two half spans, while the other has three whole spans and two half spans. The former of these has but one pier in water-way, the other pier being on the bar above Smith's Island. The other plan has three piers altogether; one of them being also located off or near the bar. The former plan will, therefore, offer the least obstruction to floating ice, though either plan will be decidedly better in this respect than the one with draw-piers, formerly reported upon. The board assumes the "port warden's line" on the Philadelphia side, and the "commissioner's line" on the Camden side, as being established water lines which they are not called upon to discuss. The profiles of the river show that the water-way has been materially encroached upon in the establishment of these lines; but, as the bridge project exhibits the shore-works of the structure as held within those lines on both banks, it is evident that their construction will not diminish the present water-way of the river. The drawings and specifications of the modified projects are herewith transmitted. I. C. WOODRUFF, Lieutenant Colonel of Engineers. Lieutenant Colonel of Engineers. Captain of Engineers, U. S. A. APPENDIX S 1. UNITED STATES ENGINEER OFFICE, Houston and Greene Streets, New York, September 8, 1871. GENERAL: In accordance with circular of June 9, 1871, from the office of the Chief of Engineers, I have respectfully to report upon the progress and condition of the works of improvement of the Hudson River between Troy and New Baltimore, during the fiscal year ending June 30, 1871. Channel along New Baltimore Dike.-The dredging of New Baltimore Channel, 5,700 feet long, 300 feet wide, was completed; 79,615 cubic yards of material, measured in scows, having been removed during the fiscal year, affording a depth of 11 to 14 feet at mean low water. This excavation was agreed to be paid for at 23 cents per cubic yard in position, and it cost the United States only 15 cents per cubic yard measured in the scows. The total amount in position, was calculated at 91,194 cubic yards; the amount removed, as measured in scows, was 133,950 cubic yards. Coeymans Dike.-This dike, built by the State of New York, was undermined and much injured for a length of 120 feet. This was repaired by the United States, but the cost, $716 24, was borne by the State com missioners. Dike connecting Schodac and Castleton Dikes.-Eleven hundred and eighty-three feet of this dike have been completed, of which 227 feet were constructed during the fiscal year. This dike consisting of 139 feet of full dike and 1,044 feet of half-dike; has been constructed at an aver age cost, including filling with stone, of $4 42 per foot. There remains to be un ertaken of this shore protection 1,952 fet. Removing Overslaugh Rock.-A contract to remove the Overslaugh Rock, containing 614 cubic yards, and situated in the channel of that name, was awarded to Emory R. Seward, of Albany, in the fall of 1870, at $13 per cubic yard. The contract was limited to June 1, but at that time the whole rock had not been removed. An abstract of bids accompa nies this report. Dredging along Overslaugh Dike and Cuyler's Bar.-For the purpose of testing the truth of a report that large quantities of cliukers, cinders, and ashes were deposited, from steamers under way, in the channels along the Overslaugh and Cuyler's Dike, I directed examination of the bottom to be made with a dredge. The result of the examination proved that a large per cent. of such materials was deposited in the said channels-more in the former than in the latter. The amount dredged in this experiment was 1,960 cubic yards, costing $403 75, from the Overslaugh Channel, and 1,080 cubic yards, costing $297, from Cuyler's Bar. Bath Dike. This dike, 3,823 feet long, commenced May 20, 1870, was finished in the fall of the same year. The average cost was $8 42 per linear foot. Patroon's Island Dike.-This dike, 3,409 feet in length, and in continuation of the old United States Dike, was undertaken and finished in the fall, during the fiscal year. It was composed of cribs, which were principally filled with dredging from the channel, and cost $3.30 per linear foot. Old State Dam.-That portion of the dam projecting into the channel, beyond the line of Patroon's Island Dike, was removed. The amount taken away was 1,289 cubic yards, at a cost of about 25 cents per cubic yard. One thousand cubic yards of this material were deposited in the before-mentioned dike. Base Island Dike.-This dike, 5,119 feet long, and situated toward the east bank of the river, was undertaken and finished in the fall, during the fiscal year. Its construction was the same as that described for the Patroon's Island Dike. The cost was $3 55 per linear foot. Miscellaneous.-Stone-filling, to compensate for settlement, was added in several dikes, and some slight repairs made to the Port Schuyler Dike. No work was undertaken from the opening of the season to the end of the fiscal year. It was considered proper to await the result of surveys before maturing a plan of improvement at several important points. Works to be undertaken during the present season.-The works which will be undertaken and probably finished during the season are 1st. Construction of dikes at Coeymans, for the preservation of the channel, along the wharves of that village; and for the improvement of that channel. Sufficient time has elapsed to show the result of the action of the unfinished works of improvement already executed. The necessity here exists of keeping open two channels; the princi pal one along the eastern bank for general use, and a smaller one, on the west bank, for the accommodation of the village of Coeymans. The information obtained from the survey has enabled me to devise a plan which will, I think, subserve both objects, but without injury to the more important. Dikes at Coeymans.-A dike is designed to connect the wharves at Coeymans with Barren Island; this dike, by arresting the discharge through the shallow channel west of Barren Island, will benefit both of the channels under consideration. Another dike along the middle ground, in the general prolongation of the Roah Hook Dike, is intended to define the position of the middle ground, which is liable to shift from time to time, and will operate directly upon the improvement of the principal channel. There is a gap left between this dike and that styled Roah Hook, through which a portion of the water passes to supply the small channel in front of Coeymans, and by the gradual contraction of this gap, a sufficient supply for such purpose, and no more, will be allowed to pass through. Should it be found that two channels cannot be kept open, the gap may be closed, and all the water thrown into the main channel. Dikes at Coeyman's.-A third dike, from the extremity of Roah Hook Dike to the wharves at Coeymans, is necessary to direct properly the flow of water, and to prevent the closing of the channel intended for the accommodation of the village of Coeymans. The estimate for the construction of these dikes, 5,500 feet in length, is $40,600; of which $37,000 can be drawn from the appropriation on hand. 2d. Dredging off the point of the middle ground, which, at present, contracts the principal channel opposite to Coeymans. 3d. Dredging a cut about 50 feet wide through Fish-House Shoal, above Albany. 4th. Leveling up the crib-dikes above Albany with timber, and completing filling with stone. 5th. Dredging a cut along Overslaugh Dike, between Overslaugh Rock and Van Wies Point. Condition of the river-Fish-House Shoal.-Fish-House Shoal, above Albany, has been reported somewhat troublesome during the season. The depth of water over this shoal, by the last survey, made in 1870, prior to the construction of the Base Island and Patroon's Island Dikes, was only 6.5 feet, at mean low water. A slight change in the direction of the channel, which would naturally follow the construction of the dikes aforesaid, would produce a decrease of depth in the former channel, and consequently in the navigable channel, until the new channel was perfectly formed. A very slight decrease of the already limited depth is sufficient to produce trouble. Base Island Dike.-The length of the Base Island Dike was never absolutely fixed, and it might prove a benefit to prolong it about 1,800 feet, costing $9,000. Increased height to dikes between Albany and Troy.-With the present low dikes, the depth over the shoals between Albany and Troy, at mean low water, will not much exceed 7 feet; but it is probable that by increasing the height of the dikes, a navigable channel of 9 feet in depth, at mean low water, may be secured. But the height of the dikes should be increased upon one side only of the channel. Condition of the river-New surveys required.-Before, however, committing one's self definitely to the idea of increasing the height of the dikes, it would be necessary to have a new survey of the whole river between Albany and Troy; and this would be useful likewise in determining the effect of the new dikes and the changes which may have taken place from other causes since the date of the former complete survey made in 1867–68. Port Schuyler Dike.-The old United States Dike at Port Schuyler is in need of repairs, costing $1,000. Shoal under railroad bridge. From the survey recommended, it will probably appear that the shoal under the railroad bridge will need re moval, in order to conform to a new set of currents, and to a more direct channel. Cost, $6,000. New railroad bridge at Albany.-Since the date of the last report, the piers for a new railroad bridge at Albany have been brought out of water. The effect of the new bridge will be, in all probability, to cause the ice-dams to be more frequent and of longer continuance, and thus create shoals above the bridges. Cuyler's Dike and Channel.-There have been complaints within the past two years of shoaling in the channel along Cuyler's Dike. This dike and channel were the result of the labors of the State commission. A survey will be made in the early part of the next season to ascertain the exact condition of the channels and the causes of its deterioration. It is probable, however, that another dike, generally parallel to the exist ing dike, will be found necessary. The utmost length required, 4,000 feet, may be constructed at a cost of $28,000. Overslaugh Dikes and Channel.-Nothing has been done in this locality beyond repairing the old United States dike. It has, however, been designed to construct a line of diking parallel to the existing dike, for a length of about 8,000 feet, at a cost of $56,000. Although detention of vessels has occurred during the past season in the channel, the results of a recent survey have demonstrated that the channel has actually increased in depth within a couple of years, and is still improving. Fur ther improvement will undoubtedly result from the complete removal of the Overslaugh rock. An old State dam along this dike, which injuri ously deflects the currents, will be removed at a cost of $5,000. Cedar Hill Dike. The gap of 1,000 feet left in this dike having ful filled its object, may now, with benefit to the main channel, be closed. The effect of this will be to close the west channel, the further existence of which would serve to retard the improvement of the main channel. Cost, $6,000. Scammerhaun's Island-condition of the river.-There may be needed here a half-dike along the eastern shore, and the cutting away of this shore to give sufficient width for the in-flow of the flood. A survey is needed to determine the character and extent of these operations. Probable cost, $30,000. Protection of Shad Island. This work, only of probable necessity, would cost $4,800. Protection of Schodac Island. The completion of this work, for a length of 1,952 feet, would cost $7,808. Dikes at Coeymans.-The necessity of these dikes has already been fully set forth. Their total length will be 5,500 feet, aud cost $40,600. The method pursued in the improvement of the river has been to construct works of primary necessity at each locality meeting amelioration, and afterward, by means of surveys, to ascertain the expediency of a further extension, and great care has been taken to avoid constructing works of doubtful utility, or which might afterward prove injurious. So far the general plan has been successful, and promises excellent results after completion. The following estimate will show the amount required to complete the improvement of the river: Deduct amount on hand available July 1, 1871...... 65, 464 64 Asked to be appropriated.. 200, 000 00 As the work for the improvement of the river approaches its completion, it is possible to perceive more clearly the total probable cost, and to compare this with the original estimates It is shown from the preceding that the cost will be within the lowest estimate made at the begining of operations upon the river. There is asked to be appropriated for the fiscal year ending June 30, 1873, the sum of $90,000, which sum will be devoted to most important objects, viz: Completion of the dikes at Coeymans; closing gap in Cedar Hill Dike; construction of dikes parallel to the Overslaugh Dike; removing old State dam along Overslaugh Dike; extension of Base Island Dike; dredging and surveying. A general survey of the river is imperatively needed. The work is located in the 14th collection district. The nearest port of entry is Albany, New York. The amount of commerce and navigation benefited is $500,000,000. Respectfully submitted. JOHN NEWTON, Lieutenant Colonel Engineers, Brevet Major General. Brevet Major General A. A. HUMPHREYS, Chief of Engineers, Washington, D. C. S 2. UNITED STATES ENGINEER OFFICE, ARMY BUILDING, HOUSTON AND GREEN STREETS, New York, September 29, 1871. GENERAL: I have respectfully to report upon the progress and condition of operations for the removal of the rocks obstructing navigation in the East River, including Hell Gate, for the fiscal year ending June 30, 1871. The condition of the shaft or pit at Hallett's Point, at the period o |