2d. To obtain a channel from the upper rolling-mill to and beyond Add for contingencies, engineering, superintendence, together with removal of sunken trees, sometimes found in the channel and not detected in the surveys, say 20 per centum.. $4,439 75 3,266 90 2,390 29 Total 14,341 74 Estimate C.-For excavation in the Thames River, Connecticut, to obtain the followresults: 1st. To obtain a channel, connecting the deep-water channel west of the Add for contingencies, &c., as before, say 20 per centum. Total.... $903 35 4,439 75 3,266 90 8,610 00 1,722 00 10,332 00 The contract price, under the contract made in 1867, for work on the Thames, and afterward continued at the same rate, by special authority of the Engineer Department, until the close of the work in August, 1869, was at the rate of 45 cents per eubic yard. It is thought, judging from similar work in this district, that at this time the same work could be done for 35 cents per yard, and perhaps even less; but supposing it could not be done for less than the original rate of 45 cents, then the foregoing estimates for the same amount of work will stand as follows: The place in which to deposit excavated material demands careful consideration. First. As regards the middle grounds, the new wharf of the Norwich and Worcester Railroad Company was filled in partly from material excavated from the trench or cut made in front of their wharf, and partly from stone, earth, &c., brought up by cars from along the line of adjacent railroad. There is still considerable filling needed to complete and properly grade the wharf, which could not be more conveniently supplied than from this shoal immediately in its front. Should there be more than is needed, it can be safely deposited anywhere to the east and south of the Pier B, where much material from the neighborhood has already been placed. If this latter were done, it is understood the railroad company would make efforts to wharf it in and thus secure it. The material taken out in front of the coal yards can also be deposited at the place above indicated, or, if there be not room enough, can be placed either on Kinney's Flats, within the line of Pier D, or taken down the river below either the Upper Rolling Mill wharf, the Lower Rolling Mill wharf, (Pier G,) or below the Sand Pier, (so called,) Pier H. At any of these locations, too, can the material excavated between the Upper Rolling Mill and Perch Rock be placed with security. The excavations from the Haycocks can be placed on the Trading Cove Flats, there being an inshore channel sufficient for scows following the west shore northward from the neighborhood of Cooper's Point. From time to time dumps have been made in all these localities, and it is believed none of the material has moved back into the channel. Further observation may indicate other and perhaps better places of deposit, perhaps below piers N and M, though at these two places there are oyster fields or beds, which, unless it is absolutely necessary, ought not to be interfered with. Further examination may show that the line of cutting may, with benefit, vary from the direction I have laid down on the map. As, for instance, it has been suggested that the channel be straightened from the head of Pier G to Bushnell's Reef, and that that across the Haycocks should be perfectly straight from the head of pier K to the point on the west shore where the channel takes the next natural bend. These schemes may be of doubtful utility. If, however, the middle ground is to be removed I would recommend that no deviation be made from the present line of deepest water until time shall have shown what effect this alteration in the upper bed of the stream will have. The mode of survey adopted was as follows: The heads of piers, the shore-line, the wharves, and prominent points had been carefully located in the transit survey of 1566, and remaining substantially the same, were used as the main objective points of this survey. Any subsequent changes in the shore-line since then were noted. I procured a quantity of fine white cod-line, which neither stretches nor shrinks materially, and marked it with white tags every 10 feet, the fifties and hundreds being marked, respectively, with red and blue tags to facilitate counting. Ranges of stakes (rough spruce scantling) were then driven in shoal places convenient distances apart, on known lines referred to known points, generally parallel to the direction of the channel Parallel to this line, another range of stakes, equally distant apart, were also placed. The graduated line was then stretched across the channel from stake to stake, and soundings taken from a small boat opposite each tag, thus giving series of soundings, 10 feet apart, at right-angles to the general direction of the channel, the lines being sufficiently near each other to enable intelligible contours to be drawn. The soundings, as plotted on the map, are generally 20 feet apart, except on the middle ground and in occasional places, where it being desirable to show the bottom more in detail, they are given 10 feet apart. The time of tide was noted, for each sounding, and these reduced to the plane of mean low water through the medium of tide-gauges established at intervals on the river, and all referred to the bench-mark of the survey of 1866. This bench-mark (mean low water) is a cut on a pile in the corner of the wharf west of the railroad bridge across the Shetucket river, and its position is indicated on the map by a red star within a circle, thus . This point should be referred to the city grade level or the water table of some permanent structure. I intended to have done so, but by some means it was forgotten. The level of mean low water, to which these soundings are reduced, was determined in 1866 from a register of the tides kept during thirty-three days, the average high tide recorded being 3.124 feet above; the lowest tide, 0.854 feet below; and the highest tide 3.77 feet above the determined plane of mean low water. This plane was fixed by a comparison of the average of the recorded high waters and low waters above aud below the assumed plane, which resulted in a minus correction of .124 feet below that plane. The bench-mark so obtained was cut into the pile already described. This mode of locating soundings by means of a graduated line is a very excellent one when the lines to be run are not too long and the current not too swift. I found, by attaching cork floats, such as are used on fishing nets, say every 50 to 100 feet, there was no difficulty in maintaining the line in a straight direction, even in swift running water. When the starting points are properly located this system gives excellent results. The character of the bottom has much to do with its execution, since, unless the bottom be such as to admit stakes being driven, (unless the river is very narrow,) it cannot be done. The bottom of the Thames, however, being composed chiefly of sand, with some mud and gravel, ("easy digging,") little troubie is experienced. The location of soundings with two instruments is, in some respect, a better method, but, as I had no transit observers with me in this work, it could not be done in this manner. I was assisted, however, in the survey by Mr. Joseph H. Lovel, of Norwich, Connecticut, who, since the work was begun in 1867, has been employed as inspector of dredging. His intelligence and knowledge of the river have rendered his services at all times of much value. The commercial importance of this river is increasing yearly. It is the natural outlet for the productions of an immense manufacturing district, and the natural inlet for the foreign importations and coastwise trade, both of which are extensive and extending. The nearest port of entry is New London, in the third collection district of Connecticut, where the amount of revenue collected for the year ending June 30, 1866, was $26,662 97, and for the year ending June 30, 1870, was $60,410 67, showing an increase of $33,747 70, which is undoubtedly owing, in a great measure, to the increased facilities to navigation already afforded in the work done since 1866 by the United States. Norwich itself is an active, enterprising city, largely engaged in manufactures, and rapidly increasing in wealth, size, and importance. Money spent by the United States in aid of the commercial interests and industrial pursuits of so thrifty a region must ultimately redound to the benefit of the country at large. I am, general, very respectfully, your obedient servant, H. A. JUDSON, Assistant Engineer in charge of Surrey. T 8. IMPROVEMENT OF THE CONNECTICUT RIVER. The condition of this improvement up to September 30, 1870, is given in my annual report of last year. (See Report of Chief of Engineers in Annual Document, pp. 446, 447, 448.) The act appropriating $40,000, under which work was then being conducted, approved July 11, 1870, did not specify any particular points at which the money should be expended, but there was an understanding among members of Congress that but $20,000 of this amount was to be expended below Hartford. The appropriation act for rivers and harbors, approved March 3, 1871, made a distinction between these two sections of the river, and appropriated $35,000 for continuing the improvement below Hartford, with a separate sum for the river above Hartford and below Holyoke. Advertisements were duly made, in 1870, for proposals to do the work under the first $20,000, as reported in my last annual report. The dredg ing was awarded to the Albany Dredging Company, and the piling at Hartford Bar to Mr. Emory R. Seward, of Albany. The Albany Dredg ing Company executed their work within the fiscal year, and the work performed by them was as follows: Excavating and removing from bar above Mouse Island 35,077 cubic yards; excavating and removing from Pistol Point Bar 16,418 cubic yards; excavating and removing from Pratt's Ferry 12,046 cubic yards; making a total of 63,541 cubic yards, at 184 cents a yard, $11,955 08. Maps accompanying this report will show the places where this dredging has been done.* Mr. Seward failed to execute his contract for the piling at Hartford Bar, and it was advertised for again, as will be seen in the abstract of proposals given further on, but no offer was made for doing this work as low as that agreed upon with Mr. Seward, and upon his signifying his willingness to go on with the work if the time of his contract was extended, the time was extended and the work is at this date in progress. The money from the appropriation of $40,000, approved July 11, 1870, is still on hand to pay for this work. The matter of the $20,000, in the act approved July 11, 1870, understood by the members of Congress to be intended for the Connecticut These, if not received from General Ellis in time to forward with this report, will be sent afterward. River above Hartford, and by some of them to be for the river in the State of Massachusetts, remained undetermined until the 16th of December, 1870, when it was decided that it might be expended in improving the Connecticut River above Hartford, beginning at that place and working upward. A survey was at once begun to determine a suitable plan of improvement. The report and maps made under my direction by General Ellis, civil engineer, were completed and submitted to the engineer headquarters on the 15th of March, 1871. This report from me and that of General . Ellis, dated March 4, 1871, are annexed to this report. The plan of improvement was to construct wing-dams at five places between Hartford and the Enfield Rapids. Further information concerning these can be got from those reports, and from the copy of the advertisement which follows. On the 29th of April, I issued advertisements for proposals under the last appropriation of $35,000 for improvements below Hartford, and for that under the $20,000 of the first appropriation to be applied above Hartford. I have reserved advertising for proposals under the appropriation of $20,000 for improving the river above Hartford and below Holyoke until the survey now being made at the Enfield Rapids is completed. |