Wilmington is a port of entry, and is in the collection district of Delaware. The revenue collected during the past fiscal year amounted to $50,530. The nearest fort and light-house are, respectively, Fort Delaware and Christiana light. Total appropriation to June 30, 1882 Total expenditures to June 30, 1882... Total estimated cost of project of January 7, 1881. $133,000 00 100, 522 22 175,551 00 Money statement. July 1, 1881, amount available... July 1, 1882, amount expended during fiscal year, exclusive of $49,843 92 outstanding liabilities July 1, 1881. $16,866 22 July 1, 1882, outstanding liabilities.. 534 12 17,400 34 July 1, 1882, amount available.... 32,443 58 Amount appropriated by act passed August 2, 1882. 50,000 00 Amount available for fiscal year ending June 30, 1883...... 82, 443 58 = Amount (estimated) required for completion of existing project. 75,551 00 Amount that can be profitably expended in fiscal year ending June 30, 1884. 50,000 00 PROJECT OF CAPT. WILLIAM LUDLOW, CORPS OF ENGINEERS. UNITED STATES ENGINEER OFFICE, Philadelphia, Pa., September 14, 1881. SIR: The accompanying plan and specifications for the jetty to be constructed at the mouth of the Christiana River are respectfully submitted for approval. In the presentation of these, it has been the endeavor to conform to the recommendations of the Board of Engineers to whom the project was referred, as expressed in their second report, dated August 6, 1881, making such modifications only as a careful study of the peculiar local conditions seemed to require, and as the Board appear willing to concede to the judgment and opinion of the constructing officer. The jetty, in accordance with the recommendation of the Board, terminates at the 12-foot curve, and is built with pile substructure and crib superstructure; the whole filled with stone. In order to give greater stability, with a slight increase only of filling, the piles are driven with an outward rake or batter of 1 in 12, and the heads thereafter slightly drawn together. The width of the jetty throughout is 12 feet at low-water, and its height 4 feet above that plane. A greater height would increase its exposure to injury and decay, and add to the cost without increasing its efficiency in guiding the ebb current. The width of 12 feet at low-water might, perhaps, be decreased shoreward, with a saving in filling partly compensated, however, by greater cost of construction due to change of dimensions and adjustment of plant. Owing to this and to the anticipation that deep water will form against the jetty near the above line, it is considered advisable to carry that stated width to the shore. The iron ties have been increased, as it is believed that the 14-inch rods, having about 1 square inch of cross-section, would not be in excess, for every 5 feet 4 inches of length of jetty to sustain the outward pressure of stone filling 10 to 12 feet in depth. It is considered that the construction of the terminal pier is desirable, even anticipating the future extension of the jetty to the 15-foot curve. It is so built into the jetty as to present no impediment to such extension. The end of the jetty will be at all times exposed to much greater action of the tides, waves, and ice than any other portion, and disintegration of the end would lead to the continuous destruction of much of the remainder. The estimates have been carefully prepared from the best attainable local data, and are believed to be ample to cover cost. If contract be made this fall, the contractor having sufficient time within which to prepare his material, will, it is thought, be able to do the work at a cost of $2,000 or $3,000 less than the estimate, bringing the expense of the jetty down to about $35,000. The $12,000 or $15,000 remaining of the appropriation of $50,000, in act of March 3, 1881, is to be applied to the continuation upward of the existing 12-foot low-water channel to the Pulp Works. A letter to the Chief Clerk, War Department, accompanied by advertisement and specifications, is therefore inclosed. re It should be stated, in case of possible misapprehension on this point, that while a considerable amount of scour along the face of the jetty will probably result from its controlling the effluent current of the Christiana, nevertheless the useful effects to be anticipated are not the " moval of the bar" at the mouth so much as the maintenance of an increased depth to be hereafter attained by dredging. The projects and estimates presupposed the removal by dredging of the necessary amount of material. Unless this is done it is doubtful whether its scouring at one point will not be compensated for by filling at another. Very respectfully, your obedient servant, WILLIAM LUDLOW, The CHIEF OF ENGINEERS, U. S. A. Bvt. Lieut. Col., U. S. A. ESTIMATE FOR JETTY AT MOUTH OF CHRISTIANA RIVER, DELAWARE. 2,229 hemlock piles, 12 to 15 inches butts by 8-inch points by 27 to 30 feet, at 18 oak piles, 16 to 18 inches butts by 8-inch points by 40 to 43 feet, at $12.. Ice shields and spikes, 1,503 pounds, at 6 cents.. Covers, heads of piles, &c. (galvanized sheet iron), 200 pounds, at 10 cents Galvanizing bolts, nuts, &c., 19,944 pounds, at 14 cents 107 10 7,402 90 1,582 29 90 18 20 00 348 97 2,041 44 Stone (20 per cent. added for subsidence), 11,374 cubic yards, at $1.40... Ten per cent. for engineering and contingencies.. Abstract of proposals received by Capt. William Ludlow, Corps of Engineers, brevet lieutenantcolonel, U. S. A., during fiscal year ending June 30, 1882, for improvement of Wilmington Harbor, Delaware. FOR DREDGING IN CHRISTIANA RIVER, WILMINGTON, DELAWARE. FOR CONSTRUCTION OF JETTY AT THE ENTRANCE OF CHRISTIANA RIVER, WIL MINGTON, DELAWARE. Abstract of contracts entered into by Capt. William Ludlow, Corps of Engineers, brevet lieutenant-colonel, U. S. A., during fiscal year ending June 30, 1882, for improvement of Wilmington Harbor, Delaware. CONSTRUCTION OF JETTY AT ENTRANCE OF CHRISTIANA RIVER, DELAWARE. Maritime business of the port of Wilmington, Delaware, from June 1, 1881, to June 1, 1882. LETTER OF COL. J. N. MACOMB, CORPS OF ENGINEERS. UNITED STATES ENGINEER OFFICE, SIR: I have the honor to acknowledge receipt of department letter of 16th ultimo, covering copy of report dated June 7, 1881, by the Board of Engineers for Fortifications and River and Harbor Improvements, in New York, to whom was referred the project from this office of April 8, 1881, for the application of the $50,000 appropriated in river and harbor act of March 3, 1881, for the improvement of Wilmington Harbor, Delaware.* This project, in conformity with the conclusions expressed in the original report of January 7, 1881, made subsequent to a somewhat extended examination during the previous summer, recommended the construction of a jetty to extend from the Light-House Dike on the north side of the Christiana entrance outward to the 15-foot low-water curve in the Delaware River, with direction and development as shown on an accompanying chart. The jetty, as proposed, was to be a pile structure filled with stone, or with mud and stone, as might be found most economical, having due regard to necessary stability and durability, with its top at 4 feet above low-water, and therefore 2 feet below high-water, and a width equal to the depth of water at low-water, the minimum width being 6 feet. See Annual Report Chief of Engineers for 1881, page 775. The cost of the jetty, as originally estimated, was $31,500, which, out of the $50,000 of appropriation, would leave a sum of $17,500 to be expended in prolonging the 12-foot low-water channel in the Christiana upward to the Pulp Works, and a remainder of about $1,000 for contingencies. It is gratifying to find that the Board, after their investigation of the subject, concur generally with the project, and confirm its recommendations as to the extension of the 12-foot channel and the construction of the jetty. The dimensions to be given the jetty constitute the main points of difference. The Board recommend that the jetty be built up to the level of high-water, or reference 6, instead of to reference 4-low water being 0-and that its width throughout be made equal to its height, instead being made equal to the low-water depth of the site outside the 6-foot curve. As these recommendations involved serious increase of cost, and the report of the Board was unaccompanied by any drawings or estimates, it became necessary to prepare these, in order to ascertain the probable cost of the work as proposed. It was evident at once upon the completion of sketch, plans, and careful estimates based thereon, that the cost of the jetty, even if stopped, as proposed by the Board, at the 12-foot curve, would exceed the total amount of the $50,000 appropriation. A series of plans was therefore considered, involving five methods of construction and nine totals, with the view of determining whether the expense of the work could not be brought within desirable limits without impairing its effectiveness or stability. The results of this investigation are given in the accompanying drawings and schedule, in which the comparison between the several methods of construction considered is made both numerically and graphically. The prices are those of to-day, and are greater than those of last year, by reason of a considerable advance both in cost of material and labor. The estimates have been carefully gone over, and while on the whole they are larger than the work can probably be done for by contract, if given out at one time for the whole work, they have been brought down to the point within which an equitable margin of profit could be made, and give an accurate idea, at any rate, of comparative cost. While submitting these estimates and exhibitions of the several methods of construction, I desire to ask a reconsideration of the recommendations of the Board with regard to the dimensions of the jetty. The increase over the dimensions recommended in the original project is illustrated by taking the case of the jetty in 10 feet of water at lowwater. According to the project, the jetty at this point would be 14 feet in height and 10 feet in width. According to the report of the Board, the height would be 16 or 17 feet, and the width the same, an increase of 83 per cent. in cross-section, with a corresponding increase in cost. The total cost of the jetty supposed to be built to the 15-foot curve, on the same methods, with the differing dimensions, is nearly double. The report of the Board does not indicate the reasons upon which their recommendations as to width and height are based. A careful study of the local conditions, and considerable knowledge of the character of other structures in the Delaware of equal, and even much greater, exposure, justify the belief that the dimensions as origi nally proposed are ample to attain all necessary strength and effective ness. The construction of the partly submerged jetty rests upon the following considerations. The Delaware, in common with similar tidal streams, exhibits a char |