The board is of the opinion that the peninsula is in no immediate danger from the action of the lake waters, but that as a measure of precaution against possible damage in case of a succession of seasons of unusually high water, accompanied with severe storms, it would be well to re-enforce those points where the 6-foot curve no longer exists, viz., near the eastern end of base-line No. 6, and at the junction of baselines 8 and 9; and as a further protection to this portion of the peninsula, the board think that the growth of vegetation upon it should be encouraged to as great an extent as possible, and for this purpose it is believed that slips of the silver-poplar or beach, which grows and multiplies its roots and suckers with great rapidity, should be used extensively, and most especially at those points where the vegetation is sparse. To cover the entire barren portion of the Neck with these would cost not less than $5,000, and to introduce the brush and stone constructions above referred to, at the low points mentioned, would probably cost as much more, and it is recommended therefore that $10,000 be applied to these purposes. The board is also of the opinion that a careful survey of the lake-shore of the peninsula should be made in the spring, and should be repeated annually for a series of years, in order to ascertain positively whether there is any law governing the changes which are perceptibly taking place in its contour, its rates of growth or waste, with a view to the establishment of some general system of protection, if necessary. The board desire to call earnest attention to the danger which threatens this fine harbor from depredations or injurious changes made on the peninsula. This is now under control of the board of trustees of the marine hospital of Pennsylvania, with power to lease, improve, and administer generally for the benefit of said hospital, with no restriction of law as to operations which may endanger the safety of the peninsula. Under this authority several houses have been built thereon, parts have been leased, timber has been removed, and it is now proposed to establish here a park and pleasure-grounds, which can only be done by clearing away trees and undergrowth necessary to the preservation of the peninsula, and, therefore, of the harbor. The board, strongly convinced of the great danger of allowing any interference whatever with the vegetation of the peninsula, are unanimous in the opinion that the attention of the legislature of Pennsylvania should be called to this matter, in order that such enactments may be made as shall secure the safety of the harbor, and prevent the efforts which have been made by the General Government of the United States for its improvement under heavy annual expenditures from being counteracted. These legal enactments should be made so as to insure the prevention of the removal of timber, either standing or fallen, brush, or drift-wood, from the peninsula or its shores. I. C. WOODRUFF, Lieutenant Colonel of Engineers. J. G. FOSTER, Lieutenant Colonel of Engineers. WALTER MCFARLAND, Major of Engineers. There being no further business before it, the board adjourned sine die. I. C. WOODRUFF, Lieutenant Colonel of Engineers. WALTER MCFARLAND, Major of Engineers, Recorder. Subject of contracts. Name of officer by whom let. D. 15.-Abstract of contracts entered into during the fiscal year ending June 30, 1871, for the improvement of harbors on Lake Erie, west of Dunkirk, New York. Andrew Spalding, Buffalo, Lewis J.Bennett, John Hand, Removing from main ship-channel through Maumee Bay, N. Y. O. J. Jennings, Syracuse, Andrew Spalding, Buffalo, C. Fitzsimons, Chicago, Ill. Lee & Dunbar, Erie, Pa. Buffalo, N. Y. Thomas Keeler, George M. Hugh W. Smith, Buffalo, Orville J. Jennings, Syra- Toledo Harbor, Ohio, 129,000 cubic yards, more or less, Removing from Sandusky Bay, Ohio, 25,000 cubic yards, Removing from the channel, between the piers of en- Removing from the channel over the inner bar, Erie Constructing, furnishing material, and putting in place Removing portion of wrecked north pier; constructing, Con- Date. D 16. Report upon the survey of the harbor of Port Clinton, Ohio, made in accordance with letter of instructions from the Chief of Engineers, dated Washington, D. C., July 23, 1870. The survey of this harbor was begun during the second week of November, and was continued at intervals, when the weather permitted, until near the closeo f that month, when the season became so cold and stormy as to prevent the soundings from being carried farther than the sketch indicates. Enough was learned, however, of the character of the channel from the point where our labors terminated to its entrance into the lake, to enable us to form an estimate of the probable cost of attempting to improve it. For a mile from the extremity of the peninsula, lying on the northern side of the river's mouth, the channel runs nearly parallel with the shoreline in an easterly direction, its only protection lakeward being a bar of shifting sand, through which it finally enters the lake. Through this channel, which is quite crooked, only about six feet water can be carried at the stage of water given by the survey. If 8 feet depth could be given here the traders would be satisfied, for not more than 6 feet water can be carried down the Portage River from the lumber-mills above, which furnish the entire trade of this harbor. A channel 8 feet deep and of sufficient width to accommodate the small vessels running here could be made at no very great expense; but it would be useless to do this, without at the same time constructing a breakwater for the whole length of the bar above mentioned, to preserve the channel so deepened from being filled in by the action of the lake waves upon its exposed flank. Such a breakwater properly built would cost not less than $250,000. The only other alternative which presents itself, then, in order to make a good harbor here, is to break through this bar at some convenient point, and by the construction of an east and a west pier extending from the shore lakewards to the necessary depth, confine the waters of the river to the new opening, which would generally be kept open for the small vessels which alone make use of this harbor. This suggestion has been made before by General Cram, and I agree with him in the location of the proposed cut, but not in the direction of the piers nor their mode of construction. By an examination of the sketch herewith, it will be seen that opposite the outer extremity of the 6-foot river-curve there seems to have been an effort made by the river-water to break through the bar. Here I would locate the new mouth, limited on the east by a pier running from 8 feet water nearly perpendicularly to the shore, and on the west by a pier starting at the same depth, and with two or three changes of direction, reaching the end of the peninsula at the mouth of the river. This would require about 4,500 feet of piering, which, from its posi tion, could near the shore-line, be built much lighter than a breakwater parallel with the shore, though at the outer ends the ordinary thickness of pier-work for these waters should be maintained. The estimated cost of this I find to be $120,000. The sketch herewith gives the proposed position of these piers. I give below a statement of the amount of commerce of Port Clinton, for the eight months from April to December, 1869, since which time it has been steadily increasing: Clearances: Steamers, 319; sailing-vessels, 274; total, 593. Tonnage, 32,800. Average tonnage, 55. Average number of crew, between 4 and 5. Estimated value of cargoes, $332,000. The number of entries is not included, because the trade is all outward. One mile above the bridge the water shoals to 7 feet and continues so for three miles, then follows one mile of 8 feet water and eleven miles of 6 feet water, which carries us to the last mill on the navigable portion of the river. From Port Clinton to this point there are on the river bank six steam saw-mills, one large stave factory, and one shingle factory. Respectfully submitted. WALTER MCFARLAND, Major of Engineers. D 17. Report upon the survey of the mouth of Rocky River, Ohio, made in accordance with letter of instructions from the Chief of Engineers, dated Washington, D. C., July 23, 1870. The survey of this river was limited to that portion of it lying below the bridge over which the main road from Cleveland to the West passes, as no part above the bridge could be rendered available for the purposes of commerce. The survey was begun in the last week of October and was completed by the middle of November; although on account of the other duties required of my assistants, Irvin Camp, civil engineer, and David Enright, civil engineer, the plotting of the field-work was not begun until the last week in December. The finished map was transmitted to the Chief of Engineers on the 20th of January, 1871. By examining that map, an outline tracing of which accompanies this report, it will be seen that in its passage from the bridge to Lake Erie, a distance of about 1,000 yards, the river divides into branches, which, after encompassing an upper and a lower island, unite again and enter Lake Erie between a high rocky bluff on the west and a low sandspit on the east. The eastern branch varies between 150 and 250 feet in width, and the western branch from 75 to 100 feet in width. The depth of water from the bridge to the head of the upper island, which on the sketch herewith is numbered 2, varies. from 2 to 3 feet. Here, however, it begins to deepen slightly, and near the foot of island No. 2, 6 feet water is found. This depth, with four slight interruptions. which are indicated on the sketch, is carried to the outer bar, where the water shoals again to nearly 4 feet. Soundings were taken over this whole area, from the bridge to the 13foot curve in the lake, at distances of 10 feet on lines averaging 100 feet apart, and borings to the rock substratum were also made at distances of 20 feet on lines averaging 200 feet apart. But one-half of these soundings and borings are plotted, every alternate one in each line having been omitted. The results attained show that the bottom consists of sand chiefly, below which, at depths varying from 1 to 4 feet, rock is found. The character of this substratum is probably not different from that of the rock forming the bluffs which border the river and the neighboring lake-shore, and which consists of thin strata of slaty material, so much broken with joints and fissures as to be easily separable. The fact that the auger frequently appeared to enter such joints seems to confirm this opinion; and I have been informed, furthermore, that this rock has been dredged out here and there, without the aid of blasting, to a depth of 8 or 10 feet. The material so moved which had been dumped along the shore of island No. 1, to prevent it from being washed away, I saw, and it appeared to be of the same character as that composing the bluffs. To make this harbor available for commercial purposes, or as a harbor of refuge, two things are essential, viz: a very large amount of dredging, and the construction of an east pier, extending from the sandspit at the mouth of the river to a point opposite the angle of the bluff on the west side. At the stage of water given by the map, which may be taken as the lowest during the year, no vessel drawing over 43 feet could cross the outer bar as at present. After passing this, although the water deepens to 10 feet in the channel off the spit, not more than 6 feet can be carried up the western branch to near the middle of island No. 1, while the passage into the eastern branch, which has about 6 feet water, is obstructed by a bar between the spit and the lower end of island No. 1, on which there is but little over 4 feet water. My estimates I have limited to a channel-way 100 feet in width, extending from the outside of the outer bar through both branches to the head of island No. 1, and from 6 to 12 feet in depth; and I give the estimated cost of doing the work on both suppositions, i. e., that blasting may not or may be required, reckoning the price of dredging sand at 30 cents per cubic yard; of dredging rock, without blasting, at 40 cents per cubic yard; of blasting, at $2 per cubic yard, and of dredging rock after blasting, at the same price as sand, i. e., 30 cents per cubie yard. |