The examination showed that near Hamill's Island, in the lower section, a dike would be required to restrict the flow of the stream to the main channel and prevent injurious interference with the action of the currents by the outflow from Mill Creek. With the $10,000 appropriated in the act of March 3, 1881, preparations were made for beginning work in this locality where the worst obstructions existed, known as Coates's Bar. The dredging contract was so drawn as without additional expense to the United States to secure the construction of the dike from the north bank to the upper end of Hamill's Island, parallel to the channel. This dike was first constructed with a total length of 723 feet, and immediately thereafter dredging operations were begun and continued until the appropriation was exhausted. The result, as shown by subsequent examinations, may be summed up as follows: The aggregate amount of material, mostly fine sand, removed was 17,000 cubic yards. A continuous channel, with a width of 85 feet and depth of 63 feet at mean low-water, was made through Coates's Bar. The upper part of the shoal, as is frequently the case early in the im provement of a stream, had somewhat filled from the increased action of the augmented current upon the disturbed bed, but there was at no place less than 5 feet of water at low-water. The dike was fully doing its work in regulating and protecting the main channel, the outflow from Mill Creek discharging back of the island and joining the river without conflict. During the ensuing year, should appropriation be made, it is proposed to complete the improvement at Coates's Bar by increasing the width of the 6-foot channel to 150 feet, and thereafter to proceed to the points above, as described in the original report. The sum of $25,000 will be required for the continuance of this work during the fiscal year 1883-'84. Rancocas River is in the collection district of Burlington, N. J., which is its neares port of entry. Fort Mifflin is the nearest fort, and the Horseshoe range lights the nearest lighthouse. Total amount appropriated to June 30, 1882. Total amount expended to June 30, 1882. $10,000 10,000 Money statement. July 1, 1881, amount available.. Amount appropriated by act passed August 2, 1882. July 1, 1882, amount expended during fiscal year, exclusive of outstanding liabilities July 1, 1881 $9,819 86 9,819 86 10,000 00 Amount (estimated) required for completion of existing project. 61, 236 00 Amount that can be profitably expended in fiscal year ending June 30, 1884. 25,000 00 Abstract of contract entered into during fiscal year ending June 30, 1832, for improvement of Rancocas River, New Jersey. Name and residence of contractor. Dredging, per Date of concubic yard. I tract. American Dredging Company, Philadelphia, Pa.. $0.55* July 8, 1881. *Price for dredging includes construction of dike. Contract completed. F 17. IMPROVEMENT OF SAINT JONES RIVER, DELAWARE. With regard to this stream, there is nothing to add to what is contained in the annual report for 1881. The department having approved the recommendation that for the reason therein set forth the expenditure of the $5,000 appropriated in the act of March 3, 1881, should be deferred until further action by Congress, no action has been taken towards applying the amount now available. Reference is invited to the accompanying report of the survey of the Murder Kill, in which the improvement of both entrances is discussed. Saint Jones River is in the collection district of Delaware, the nearest port of entry being Wilmington, at which the revenue collected during the past fiscal year amounted to $50,530. Its nearest fort and light-house are, respectively, Fort Delaware and Mahon's River light. Total appropriation to June 30, 1882. $5,000 00 167 90 Money statement. July 1, 1881, amount available.. July 1, 1882, amount expended during fiscal year, exclusive of outstanding liabilities July 1, 1881. July 1, 1882, amount available... $4,902 70 20 60 4,882 10 30,000 00 Amount (estimated) required for completion of existing project...... F 18. IMPROVEMENT OF THE SUSQUEHANNA RIVER, PENNSYLVANIA. During July, 1881, the contract of September 20, 1880, for the completion of the North Branch of the Susquehanna, was completed by the removal of 3,661 cubic yards of clay and gravel from the shoal near the foot of Wilkes-Barre Island, and the paving of 425 linear feet of the dike at the head of the island to intercept the low-water flow down the north channel. This work completed the projected improvement of the river as far as Wilkes-Barre. Under the appropriation of $15,000 made in the act of March 3, 1881, and the project submitted from this office under date of June 17, 1881, advertisement for proposals for a continuance of the work was made June 25, 1881, but no bids were received. The call was repeated by circular letter, and on September 6, 1881, contract was made for the dredging of a channel above Wilkes-Barre through "Gas House Riff," "Hillman's Riffle," and the shoals between Forty Fort and Monockonock Island. The channel dimensions in view were a width of 60 feet and a summer stage or low-water depth of 3 feet. In order to avoid as much as possible the disadvantageous reduction of the water-line above the cuts through the shoals, the gravel dredged from the channel was deposited in such manner as to form submerged dikes or deflectors to back the current and direct it into the cuts. The dredging plant on the North Branch of the Susquehanna consisted of a single dredge of small capacity owned by the canal company. In consequence the contractor, Mr. R. C. Mitchell, made arrangements to build one, the construction of which delayed the commencement of the work. Dredging began in October, and after completing the channel through "Gas House Riff" by taking out 2,354 yards of heavy gravel, the high stage of the river compelled a suspension until April, 1882. An extension of time for completion was given to August 20, 1882. Up to June 30, 1882, 6,042 cubic yards of gravel, sand, and bowlders had been dredged from Hillman's Riffle and Forty Fort Shoal. The work in progress will have been completed in August, proximo, and the survey will be made, as the stage of river may allow, to exhibit the results attained. With regard to the future improvement of this stream, it appears desirable to say that the work, in accordance with the method of operating hitherto in progress, has reached a point where, if it is to be continued, a change of plan is necessary. The problem is one of the improvement of the navigation of a freshwater stream, with a strong slope and current, alluvial and drift shores and bed, great variation in level at different seasons, and in winter heavy ice gorges. The average slope between Pittston and Wilkes-Barre is about 14 feet to the mile, the fall, as usual, being taken up by a succession of pools and "riffles" or bars. During high stages the surface rises 20 to 30 feet above the summer stage. In this connection the following extract is made from my report of April 1, 1882: The method of operating hitherto has been to make narrow cuts 40 to 60 feet wide through the bars, using the materials (cobbles, coarse gravel, and sand) to direct the low-water flow into the cuts, and when islands divide the currents, to concentrate the low-water flow into one channel by means of low dams across the other. These methods, however, are of limited application only, aud owing to the loose character of the bed and banks, and the eroding and transporting power of the stream at high stages, cannot be expected to secure permanent results. Furthermore, although they have, for the time qeing at least, effected a substantial improvement of the navigation from Wilkes-Barre downward, the favorable influence of the dam at Nanticoke contributing to this result cannot be overlooked, and as the pooling due to this dam terminates near Richard's Island, it is not certain that the simple system of operating hitherto pursued will avail to any great distance above Wilkes-Barre. For a continued systematic treatment of the stream it is nearly certain that (raised) dams at intervals will be indispensable, and the construction and maintenance of these will constitute the most serious and costly part of the undertaking. To guide the judgment of the engineer intrusted with the direction of work of this character, it is essential that the limiting condition of the problem should be clearly defined, in order both that an intelligent comprehension of its nature and extent may be formed and that the detailed information necessary to its solution may be collected and thoroughly digested. It seems proper to say that in my judgment Congress should be asked to indicate with what view and to what extent the improvement of the North Branch of the Susquehanna is to be considered; and if seriously undertaken, to make provision, first, for the careful surveys and examination necessary to determine the proper methods of permanent improvement, and afterwards to appropriate such sums as shall be requisite for its annual progress in execution. With the opening of a channel through the Forty Fort Shoals, which will be completed during this season, the current appropriation will have been exhausted. The effect of the operations of this time will have been to afford a 3-foot low-water navigation from Richard's Island upwards past WilkesBarre to near the foot of Monockonock Island, 4 miles above, where lie the bars and "riffs" known as the Ram's Horn, on which the fall is 3 feet. The cuts already made are available for navigation so far as depth of water is concerned. But one of the defects of the system of narrow chutes and deflecting dams is already shown in the fact that the velocity of flow through some of them is so great as to make it difficult for the small steamboats plying on the Susquehanna to ascend them, while to open them to a greater extent would lower the pool above, and consequently increase the slope of the next rapid. In case of future appropriation for this work, I would recommend that the subject be thoroughly considered in reference to the extent of river to be improved and the low-water depth to be secured. Total appropriations to June 30, 1882.. Money statement. July 1, 1881, amount available.. July 1, 1882, amount expended during fiscal year, exclusive of $30,000 00 19,094 60 $19,344 56 $11,697 04 2,392 14 14,089 18 5,255 38 15,000 00 Amount appropriated by act passed August 2, 1882 Amount available for fiscal year ending June 30, 1883. 20, 255 38 Abstract of proposals (informal) received August 4, 1881, for dredging in Susquehanna River, Pennsylvania. Abstract of contract 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 Susquehanna River, Pennsylvania. Name and residence of contractor. Dredging, price per cubic yard. Date of contract. Robt. C. Mitchell, Wilkes-Barre, Pa.. 90 cents through Gas-House Riff, 75 September 6, 1881. cents through other shoals. F 19. CONSTRUCTION OF PIER IN DELAWARE BAY, NEAR LEWES, DELAWARE. The river and harbor act of March 3, 1881, appropriated $10,000 for continuing the construction of this work. The appended report by Mr. Stierle, assistant engineer, shows the application of the funds and the condition of the works at the end of the fiscal year 1881-'82, and submits an estimate of the additional amount necessary to complete it. The deterioration of the timber superstructure, to which attention has been invited in repeated annual reports, has progressed rapidly during the past year, and has at this date assumed such proportions as in effect to compel the rebuilding of about three-fourths of the dock. The last annual report estimated the cost of completion at $13,000. The progress of deterioration, as hitherto reported, and additional defects discovered in the course of rebuilding, necessitate increasing this estimate by nearly 50 per cent., to $19,000. It is urgently recommended that such amount as may be essential to complete this work be appropriated, since the annual deterioration and the cost of maintenance represent a large percentage of the total required. The tests of creosoted timber submerged in the harbor and exposed to the teredo, which were reported on pages 818 and 819 of the annual report for 1880, have been continued. The couples, consisting each of a creosoted and an untreated block, were again submerged April 30, 1881, and allowed to remain until November 11, 1881, when they were taken up for the winter. In May, 1881, when I had an opportunity to examine them, the nat ural blocks were thoroughly perforated, and had lost over 50 per cent. of their weight; the creosoted blocks were unchanged either in appearance or weight. New blocks of natural timber were prepared and the couples again immersed in the water, near the end of the pier, where they still remain. This work is in the collection district of Delaware, the nearest port of entry being Wilmington, Del. Fort Delaware is the nearest fort, and the Breakwater light is the nearest light July 1, 1882, amount expended during fiscal year, exclusive of out standing liabilities July 1, 1881. July 1, 1882, outstanding liabilities $8,927 16 $7,468 11 7,653 11 1,274 05 13, 000 00 Amount available for fiscal year ending June 30, 1883.. Amount (estimated) required for completion of existing project 14,274 05 6, 000 00 Amount that can be profitably expended in fiscal year ending June 30, 1884. 6,000 00 Abstract of contract entered into during fiscal year ending June 30, 1882, for construction of pier in Delaware Bay, near Lewes, Del. REPORT OF MR. A. STIERLE, ASSISTANT ENGINEER. PHILADELPHIA, PA., July 2, 1882. SIR: I have the honor to submit the following report upon the construction of the pier in Delaware Bay, near Lewes, Del., for the fiscal year ending June 30, 1882. The proposed work for the season was: To drive the remainder of the fender-piles, and connect them with the superstructure, and to replace decayed stringers, crossbeams, and floor-joists in the pier-head with new material. |