Imports at Ahnepee, Wisconsin, for the year 1870. General merchandise, $500,000. Arrival of vessels, 200; steamers, 34, propellers, 192. WM. T. CASGRAIN, Assistant. Corps of Engineers, U. S. Army, Milwaukee, Wisconsin. A 24. UNITED STATES ENGINEER OFFICE, GENERAL: I have the honor to submit the following report of an examination of Grand Marais Harbor, Michigan, made in pursuance of the act of Congress approved March 3, 1871. Grand Marais Harbor is situated on the south shore of Lake Superior, about forty-nine miles west of White Fish Point, and forty miles east of Grand Island Harbor. The only harbor affording a refuge for vessels navigating Lake Superior, between White Fish Point and Marquette, a distance of one hundred and twenty miles, is Grand Island. Grand Marais Harbor seems to have been formerly a part of the Lake, and is now separated from the lake by two narrow tongues of land formed of the lake drift. The western tongue is much larger than the eastern, and is composed of sand and sitnall boulders. The whole length of the harbor is two miles, and the width at the widest part about 2, 000 feet. The entrance is about 3,000 feet wide, and the deepest water on the bar 7 feet. The water in the harbor is from 30 to 50 feet deep very near the shore. No survey has been made of this harbor since the lake survey of 1867. I submit herewith an enlarged copy of this survey, giving proposed location of piers for improving the entrance. I made an examination of this harbor on July 22, 1871, and found that no essential changes had occurred since the survey. The position of the channel varies from time to time. When I was there the channel was much nearer the eastern point than is shown on the map. The piers are so located on the map as to give the minimum amount of pier-work, and it will not be neces sary to dredge for placing the cribs. It also allows the sea to spread out immediately after passing the ends of the piers. The estimated cost of improving this harbor is as follows: 2,400 feet of pier-work, 20 feet wide, at $40. 1,500 feet of pier-work, 25 feet wide, at $75. 1,400 feet of pier-work, 30 feet wide, at $120. Dredging 175,000 cubic yards at 35 cents.. Contingencies, 10 per cent.. $96,000 112,500 168,000 61, 250 It will be seen from this estimate that owing to the wide entrance of this harbor, and the long distance to which the piers must be extended in order to reach 18 feet of water, the improvement in the manner described, which seems to be the most economical that can be desired for a complete work, will cost more than a purely artificial harbor at a point on the coast where the water is bolder, and no dredging, and a less breadth of pier necessary. It is possible, though not certain, that a single pier in the position marked XY would have the effect to improve the entrance during northwesterly gales; which would drive the water into the harbor and scour out a channel along the pier. This, however, is uncertain and if the anticipated result did not occur, it would be necessary to build another pier, and to dredge out a channel, at a total cost not less than that of the project submitted. The only inhabitants at Grand Marais are a few fishermen, so that the only object of improving this harbor is to afford a harbor of refuge between two points on the shore eightynine miles apart. Vessels going east, or encountering northeasterly gales, can run to Grand Island Harbor; while those going west can in like manner take shelter under White Fish Point. While a harbor at this point would doubtless be very convenient, it Brigadier General A. A. HUMPHREYS, UNITED STATES ENGINEER OFFICE. Chicago, Illinois, September, 27, 1871. GENERAL: I have the honor to acknowledge the receipt of your letter of the 16th instant, calling for additional information in regard to Grand Marais Harbor, Lake Superior. In regard to the substitution of two parallel piers located on or about the line of those in my plan, for the plan I proposed, I think that there will be little, if any, saving of cost, for the reason that the beds for the cribs will require dredging, and the cribs will have to be much deeper than those composing the oblique piers which I propose. The saving in length of pier will be more than counter-balanced by increased cost of dredging and cribs. I submit the following estimate of cost of parallel piers in this locality from a depth of 15 feet inside to a corresponding depth outside. Estimates for building two parallel piers 600 feet apart at the present entrance to Grand Marais. Mean depth of dredging below water, 57 including space for sinking cribs, 660 feet. feet water, 1,500 feet. East pier 1,300 feet, 20 feet base. West pier 900 feet, 20 feet base. 2,200 feet of piers, 20 feet base, at $50. Add 10 per cent. for contingences... feet. Width of dredging, Length of dredging to 14 $110,000 00 82,500 00 72, 891 00 265,391 00 26, 539 10 291, 930 10 Moreover, I think it will be necessary to connect these piers with the shore in order to secure the proper protection, which will involve additional expense. My plan had for its object to make the entire harbor of Grand Marais available for anchorage. As, however, this harbor is much more spacious than is needed at present for a harbor of refuge, it will be possible to effect an improvement at much less cost than my estimate, by considering the western portion of the harbor only, and improving that. I inclose a tracing showing the proposed location of two parallel piers, and a cut through the tongue of land which forms this part of the harbor. It will be observed that the length of piers required is much less than at the present entrance, and a cut of 150 feet in length only is necessary to connect the waters of the harbor with the lake. I have made the distance between the piers but 300 feet, for economy of dredging. The following estimate of cost is submitted for this improvement: Estimated cost of building two parallel piers, 600 feet apart, and cutting a new channel across the point. Average depth of dredging below water, 6.65 feet; width of dredging, including space for sinking cribs, 660 feet; length of dredging, to 14 feet water, 500 feet; length of dredging on point, 660 feet; width of point, 150 feet; mean height above lake surface, 5 feet + 14 feet = 19 feet. East pier-cribs, 20 feet base = 700 feet. 1,400 feet of crib-work, 20 feet base, at $50.. 400 feet of crib-work, 25 feet base, at $75. 89,405 cubic yards dredging in Lake Superior, at 35 cents. 70,564 cubic yards dredging on point, at 30 cents... Add 10 per cent. for contingencies... $70,000 00 30, 000 00 31, 291 75 21, 169 20 152, 460 95 15, 246 09 167,707 04 The width of channel may be lessened and the cost of dredging diminished. The two narrow tongues of land which form the protection to this harbor are evidently formed by the lake-drift, produced by northWesterly and northeasterly winds. The eastern tongue is fine sand. above the water-level; but in the lake, below the water-surface, there is small gravel. This tongue or sand-spit has not changed materially since the survey of 1867, as shown by the position of the wreck noted in the survey, which is still visible. The western sand-spit is composed of sand, gravel, and cobble-stones, and the shore to the west of the harbor is composed of the same materials. The wind being quite strong from the northwest at the time I visited the harbor, I was enabled to observe the action of the waves, the effect of which is to stir up the sand and shingle, and, by striking the shore obliquely, to cause a strong littoral current, carrying the material stirred up by the waves, and held by them temporarily in suspension, to the eastward, and dépositing it at the point, the coarser material being dropped first and the finer carried round until it also is deposited. Passing round the point of this tongue of land, the material becomes finer and finer until the smooth water is reached, where there is only sand. I have had occasion to observe this action closely in Lake Michigan, and have no doubt but here tongues of sand are formed by the drift of shingle during northeasterly and northwesterly storms, and that the action is still going on. The northwesterly winds being most prevalent, as shown by the inclination of trees near the shore, accounts for the greater extension on the western side of the harbor. I have no doubt that the extension is still going on, though I have no data for determining its rate, as no instrumental survey was deemed necessary for determining the question of improving this harbor. The only accurate information I have been able to obtain has been from the lake survey. The only inhabitants are fishermen, in the summer season, and very little could be elicited from them. I find the following note on a map of Lake Superior in my possession, which I think is taken from Bayfield's chart: Grand Marais, the channel is 15 fathoms wide, and 3 feet deep at the entrance, but the bar of the Grand Marais varies with every gale. It has seldom more than three feet of water. Such is about the tenor of all the general information that I have been able to obtain on the subject, and it seems to me apparent that the changes which take place in the bottom of the entrance to this harbor must be irregular and subject to no law. The location of piers for the improvement of the harbor entrance is to be considered with reference to economy and convenience of access. I am, general, very respectfully, your obedient servant, Brigadier General HUMPHREYS, Chief of Engineers, U. S. Army, Washington, D. C. APPENDIX B 1. Annual report of Captain F. U. Farquhar, Corps of Engineers, for the fiscal year ending June 30, 1871. 1. REPORT OF OPERATIONS AT AUX BECS SCIES HARBOR. The wings on east ends of north and south pile revetments were each extended 210 feet. After due advertising and opening of proposals a contract for furnishing timber and stone was, November 11, 1870, awarded to C. S. Stevens, and on April 17, 1871, to William Nicolls, for framing and sinking three cribs, 64 feet by 20 feet. Nicolls has already sunk one crib on the north pier extension, and would have sunk another had it not been for the non-fulfillment of Stevens's contract. Stevens's contract being annulled, I at once proceeded to buy timber and stone in open market, and purchased it at the same rates as contracted for by Stevens. Under a contract made with T. Stewart White, dated May 5, 1871, the channel between the piers has been dredged to a depth of 12 feet below the surface of the water, which is not shown on the accompanying tracing, as the survey was made before the dredging had made any headway. The detailed cost of the work for the past fiscal year was as follows: 8,320 linear feet piles, at 73 cents per foot.... 2,2334 cubic feet pine timber, at 133 cents per foot. $624 00 301 53 8 100 100 3,336 cubic feet hemlock timber, at 117 cents per foot... 66 cords stone, at $9 87 per cord .. 10835% 3 cords slabs, at 50 cents per cord Tools... Driving 351 piles, at $1 each Framing 4,160 linear feet timber, at 12 cents per foot.. Filling 558.89 cords brush into pier, at 97 cents per cord.. Superintendence Advertising Total..... Amount on hand, July 1, 1870 .... Appropriation approved July 11, 1870 $393 02 5 43 115 05 119 81 2,692 51 651 42 54 19 64 28 351 00 499 20 4, 180 80 225 00 542 12 .69 76 681 72 991 86 152 25 12, 714 95 $8, 280 90 10,000 00 10,000 00 Appropriation approved March 3, 1871. Less amount covered in the Treasury of appropriation for repairs, &c., by act approved July 12, 1870..... Which amount will be entirely exhausted during the present season. During the present season two cribs 64 feet by 20 feet in plan will be placed, one on each pier. To make the improvement of this harbor complete, the piers should be further extended as recommended in my last report; the north pier 264 feet, and the south pier 328 feet, and the whole of this should be done in one season, so as to push beyond the bar. The channel should also be dredged to a depth of 14 feet. This work would cost $56,000, which can be profitably expended during the fiscal year ending June 30, 1873. Anx Becs Scies, or Frankfort, is in the collection district of Michigan, and the nearest port of entry is Grand Haven. Its nearest light-house is on Point Aux Becs Scies, or Point Betzie, as it is generally known. |