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that they were in negotiation with certain parties to construct wharves along the west side of Seekonk river, above Washington bridge. Steps were therefore taken by the Harbor Commissioners towards the establishment of a harbor line in that locality. Mention was made in our last annual report of various hearings with engineers, representing the city, and with the Brook street district Committee, in regard to the proposed constructions. The harbor line having been established, it was proposed by the city to excavate a trench in the mud, on a line parallel with the harbor line, and a suitable distance back from it, to a considerable depth, and then to fill with material taken from the Brook street district, and to protect the slope towards the channel by riprapping it with large stones. This scheme the Committee asked the Board to approve. The mud is very deep and soft at this point, and it is believed that the hard ground on which the mud rests slopes rapidly towards the channel. It was the opinion of the Commissioners that such filling would be objectionable, between Bower street and India bridge, without some bulkhead or proper retaining wall. The Committee, however, expressed their confidence that the displacement of mud by the filling would be comparatively slight, and that such displacement as would occur would be mostly by the vertical settlement of the filling. The importance to the city of this ground as a place of deposit for surplus material from the Brook street district was urged, and the Commissioners finally assented to a provisional license for the work, under which the city should become responsible for all material displaced beyond lines approved by the Commissioners, and enter into a contract to dredge an equal amount from the river and harbor at such places as the Commissioners should direct, and to their satisfaction. This contract would quite protect the public interests, and at the same time relieve the Board from the responsibility of preventing work which the representatives of the city considered desirable. The provisional license was issued on the second day of March, 1878, and the contract, in accordance therewith, bore the same date, though it was not executed until some months later. The contract bore the approval of the Attorney General. ('opies of both documents may be found annexed to Appendix D. The work proceeded, and the result more than justified the opinion of the Harbor Commissioners that a great lateral displacement would occur. The amount of filling put into the work is stated by the City Engineer at 36,800 yards. The amount remaining in the work, above the original surface and back of the lines approved by the Harbor Commissioners, is stated at 3,900 yards. It thus appears that about nine-tenths of all the filling placed here by the city has gone out into the river beyond the approved lines, or displaced an equal amount of other material. The position approved by the Harbor Commissioners for the embankment, was sixty-five feet back of the harbor line for the top of the slope at a level six feet above mean high water. The outer slope, which was to be protected by a rip-rap wall of large stones, was to be at the rate of one and onehalf horizontal to one vertical. In July last, the effect of the filling appeared to have raised the bottom of the channel opposite the middle of the work for a distance of more than two hundred feet outside of the harbor line, and about sixty feet from the harbor line the channel had been filled about seventeen feet above its former level. Nearly opposite the lower portion of the work, the filling of the channel was about eighteen feet or more in depth at a distance fifty feet outside of the harbor line. It is probable that the swift current near this filling constantly washed away the surface of the mud as it was pressed out into the channel, and that the real movement of the bottom was greater than the above figures indicate.
The proposed work is far from complete. The larger portion of the area inside the embankment is at about, or in places several feet below, the level of high water, while it was intended to be six feet above it. The outer slope is from ten to forty feet or more beyond its approved position, and even in its present condition the work is not yet quite in equilibrium, but still settles and has a slight movement laterally. The filling back of the embankment, as proposed, will add a new load, and the dredging away of the earth at the foot of the embankment will remove a present support.
The contract provides for the completion of this work to the satisfaction of the Harbor Commissioners, and also for the removal of an amount of material equal to that displaced from the river or harbor, at such places and in such manner as the Harbor Commissioners may direct, before the liability of the city is discharged.
Similar filling, under similar conditions, but with much less extent of displacement, has been done by the city a little farther up the river than that above described. Dredging has been done here by the city, to remedy the injury caused by the filling, and the Harbor Commissioners have expressed their satisfaction with it.
The harbor line established on the west side of Providence river by act of the General Assembly, passed April 27, 1878, left a portion of the Dorrance street wharf as an encroachment into the river. On the 8th of May, a representative of the wharf property appeared before the Board, and stated his wish to repair this portion of the wharf and put it into a condition so that use could be made of it. He was informed that authority could not be granted for him to proceed with any construction beyond the harbor line, and if he persisted in going on with the work, the attention of the Attorney General would be called to the matter. A petition is now before your honorable body to make a change in the harbor line, to give relief in this case. Some repairs were made, but no action has been taken in regard to the matter by the Commissioners, pending your action upon the petition.
The following licenses to build wharves have been issued:
1. March 2, (provisional) to the city of Providence, to build an carth embankment, protected by a riprap wall, on the west side of Seekonk river, northerly from Front street, a distance of about 400 feet.
2. April 10, to the Compressed Asphalt Block Company, for pile wharf, 104x108 feet, near India street, west of Ives street, in Providence.
3. May 1, to Alexander Duncan, to rebuild and repair “ Butler's wharf,” near Dyer street, in Providence.
4. September 25, to Maguire Brothers, for 60x50 feet pile wharf and wall, in East Providence, on the Seekonk river, above Washington bridge.
5. October 9, to Darius Goff, for about 180 feet of wharf retaining wall, along the harbor line on the east side of the river, in Pawtucket.
6. November 20, to the Lonsdale Company, to rebuild a portion of their wharf, 150x50 feet, near India street, in Providence.
TIDES IN SEEKONK RIVER.
There is evidently great obstruction to the flow of the Seekonk river near its mouth, by artificial constructions at India Point. The current is made so swift and irregular by the bridge piers and foundations that navigation during the ebb and flow is very difficult and dangerous and is rarely attempted. The volume of tide water passing into the large receiving basin above these bridges is much lessened by the obstructions, and thus the advantage of its scour in the channels is lost. The United States Advisory Council considered the propagation of the tides at this point worthy of study and they recommended comparative guagings. Tide guages were accordingly established about the first of September, at points indicated on the accompanying plan of Providence Harbor, by Numbers 1, 2 and 3. No. 1 is on the Boston and Providence R. R. Co.'s wharf, below the bridges. No. 2 is between them, and No. 3 is at Carpenter's wharf above the bridges. Observations were begun on Sept. 4, and continued until October 7, exceeding therefore a complete lunation. During week days readings were taken at each of these stations every twenty minutes, by a special observer, from 5 A. M. to 7 P. M., and at night and on Sundays, officers of the Providence police, through the kindness of the Mayor, took times and measurements of high and low water.
The readings obtained were measurements from a fixed point to the surface of the water as it stood in a protecting box, and were made by using a graduated rod, having a hollow copper sphere attached to float its zero at the water line. The fixed point was at the same level at the three boxes, and was eleven feet above the zero of the benchmark on the western abutment of the Railroad Bridge, established by the Coast Survey in 1874.
Measuring along the channel, Station 2 is 400 yards from Station 1, and Station 3, 300 yards from Station 2.
The observations have been platted and studied, and yield the following results, 'which should be prefaced by the statement that the range of tide was obtained by a simple average of the heights of high and low waters during a period of 294 days, or one lunation ; the figures for springs by combining the reading for those tides which occurred on days when the moon's transit fell between 0 and 14 A. M. and P. M.; and the figures for neaps by combining the readings for those tides which occurred on days when the moon's transit fell bətween 6 and 77 A. M. and P. M.
At Station 1. The average reading for high water was 6.28, for low water 10.84, giving for the mean range 4.56 feet.
The spring tides during the lunation rose above the mean high water level of the observations 0.63 foot, and fell below the mean low water level 0.65 foot, giving a range for springs of 5.84 feet. The neap tides did not rise to the mean high water level by 0.32 foot, nor fall to the mean low water level by 0.81 foot, giving a range for neaps of 3.43 feet. High water occurred at No. 1 on an average at 8 hours, 7 minutes, after the moon’s meridian passage.
At Station 2. The average reading for high water was 6.28, for low water 10.78, giving a mean range of 4.50 feet. The spring tides during the lunation, rose above the mean high water level of the observations 0.61 foot, and fell below the mean low water level 0.61 foot, giving a range for springs of 5.72 feet. The neap tides did not rise to mean high water level by 0.32 foot, nor fall to mean low water level by 0.80 foot, giving a range for neaps of 3.38 feet. The tide at No. 2 was generally observed to commence rising a little later than at No. 1, and less rapidly, so that at three-quarters tide-observed to be usually the time of greatest difference on the flood-it lagged five minutes behind the No. 1 tide at neaps, and ten minutes at springs. High water was not attained at No. 2 till after it had been attained at No. 1 by times varying from five to twenty-five minutes.