and with Mr. J. W. McComb, of St. Paul, for the "Fort Ridgely section," which extends from the eastern boundary of Sibley county to Fort Ridgely-they having been the lowest bidders for the same. The work is to be completed on or before the 30th of November next. No further appropriation will be required to effect the object indicated in the law making the appropriation. 6. Road from Fort Ripley, via Crow Wing river, to the main road leading to the Red River of the North. This road is to extend from Fort Ripley, via Crow Wing river, in a northwestern direction so as to intersect the main road leading from Sauk rapids to the Red River of the North, near Wild Rice river east, the distance being probably about one hundred and sixty miles. This road is now being surveyed and located by Mr. George H. Belden, assistant surveyor and engineer, as expeditiously as the difficulties attending it will allow. When last heard from he had reached the last crossing of Crow Wing river, distant about forty miles from Fort Ripley. This road is one of the most important to be made in Minnesota Territory, connecting, as it will, the Upper Mississippi with the navigable waters of the Red River of the North. It will be indispensably necessary for the transportation of troops and supplies to the new military post to be established on that river under the appropriation made by Congress at its last session, and of the highest importance to the large and increasing trade with Pembina and the Selkirk settlement, as well as with numerous other settlements now being established in the valley of that extensive and navigable river. The survey and location of the road being still unfinished, an accurate estimate cannot now be made of the amount which, in addition to the $10,000 heretofore appropriated, will be necessary to complete it. The amount of $25,000 can be expended to great advantage in its partial, if not its entire, construction. It is therefore to be hoped that Congress will bestow upon it the attention to which its importance entitles it, and appropriate at an early day the amount necessary for its completion. 7. Road from Swan river to Long Prairie. This road extends from the Mississippi river, near the mouth of Swan river, to the old Winnebago agency, at Long Prairie, a distance of twenty-eight miles. It is entirely completed. I have also to report that there exist no arrearages on any of the works under my charge. Their monetary condition is exhibited in the following tabular statement, showing the amounts which have been appropriated since their commencement, and their available resources on the 1st of September, 1857, together with the additional amount required for their completion. APPENDIX F. Annual report to Bureau of Topographical Engineers; 1st and 2d, St. Clair Aats; 3d, St. Mary's river; with an epitome: By A. W. Whipple, Captain of Topographical Engineers; September, 1857. OFFICE OF ST. CLAIR FLATS AND ST. MARY'S RIVER IMPROVEMENTS, Detroit, Michigan, September 1, 1857. SIR: I have the honor to submit the following annual report of operations upon works with which I am charged : 1. Deepening the channel over the St. Clair flats. The sum of forty-five thousand dollars was appropriated for this improvement July 8, 1856. I was assigned to the duty October 8, 1856, but detained in Washington for the completion of other operations until the 1st of November following. The extracts here given from the correspondence relating to this subject will serve to explain the causes of delay in the commencement of the dredging operations. DETROIT, January 8, 1857. SIR: In compliance with your directions of 30th ultimo, I have examined the charts of the St. Clair flats, just completed in the office of the lake survey, and hasten to communicate my views with reference to the most available channel for improvement, with an estimate of the probable cost, and present a plan of operations for the expenditure of the appropriation at present available. There is less time for the consideration of these subjects than I would desire, but the period when active operations upon the flats should commence is rapidly approaching, and the outfit machinery for the work should be collected without delay; hence the system to be adopted which is the basis upon which the preparations depend, ought to be distinctly marked out and clearly understood at the earliest period practicable. I shall therefore refer very briefly to the points above mentioned. 1. With regard to the best channel for improvement. It is well known that the North Pass is at present generally used by vessels navigating the lakes, on account of its superiority in depth of water upon the bar. Its course, however, is very circuitous, and the distance great where dredging would be necessary for its improvement. Less expense would be required in deepening the channel which leads to the South Pass; and, as the distance is shorter by that route, all the navigators and others with whom I have conversed upon the subject prefer to have it improved. Besides, the report of the board of engineers to the chief topographical engineer in 1854, recommending the improvement of the middle channel of the South Pass, was approved by the Secretary of War; and I see no new facts elicited by the examination of the recent lake survey charts to render it desirable to reconsider the question. 2. With reference to its probable cost. For the consideration of this subject I shall again adopt the views of the board of engineers, as reported to the chief of topographical engineers, and approved by the Secretary of War in 1854, viz: to dredge so as to give a channel 300 feet wide at bottom and 12 feet deep, the sides having an equal slope to those of the natural channel. For making this estimate, the officer commanding the lake survey has, according to your directions, afforded great facilities, and, at my request, a chart of the debouchure of the St. Clair river, by the South Pass, has been made upon an enlarged scale, from which profiles across the flats have been constructed with considerable accuracy. These profiles have enabled the assistant upon the survey to compute with much precision the actual quantity of excavation necessary to obtain a channel of the required dimensions, viz: 300 feet wide and 12 feet deep. The amount obtained from this computation is 144,250 cubic yards. This is exclusive of the side slopes. By the slopes of the natural channel, I understand the board to mean that inclination which the sides of the excavated channel would naturally assume when exposed to the action of the current and waves. It cannot be accurately determined without further examinations of the material of which the flat is composed, but it will not probably exceed an inclination of 1 in 20. Upon this hypothesis I have taken the elements from the lake survey chart and computed the side cutting required, which amounts to 49,713 cubic yards. To obtain such a slope it would be necessary to dredge from each side of the proposed channel over a space of variable width, the maximum being 120 feet. By this excavation about 60 feet would be added to the width of the channel way, giving a depth of water exceeding 10 feet, thus increasing the facilities for navigation by allowing vessels to pass each other without risk of collision. The length of channel to be dredged, according to the results of the lake survey, is 4,175 feet. The width of channel required is 300 feet, the depth 12 feet. The amount of excavation necessary to be provided for, as stated above, is For channel...... For side slopes (nearly). Total....... 144,250 194,000 cubic yards. It will be perceived that the amount of material to be removed, as determined by the survey of 1856, greatly exceeds any previous estimate. Hence the expense of the operation will necessarily prove greater than has been anticipated. Estimated cost of excavation. For two additional dredging machines, at $12,000 each....... $24,000 For nine scows (three to each dredge,) at $700 each..... For one steam-tug... For repairing old dredging machine and equipping... 6,300 17,000 2,000 For excavating 194,000 cubic yards of earth, at 18 cents per yard.... 34,920 For office rent, stationery, &c., &c....... 2,180 For contingencies, repairing machinery, &c., at 10 per cent. 8,600 95,000 In the above statement I have provided for a larger outfit of machinery than others have given in their estimates, in order to hasten the work to a rapid conclusion. It is my opinion that, if the work is to be done, it should be executed quickly, and thus remove, as soon as possible, this great obstruction to the commerce of the lakes. The boats and machinery, when needed no longer for this work, may be transferred to another, or sold, and the proceeds restored to the treasury. With the outfit proposed, the channel way, with its side slopes, may be completed, in accordance with the estimates, in two working seasons. When opened, the current through it would necessarily have an increased velocity, and tend towards preventing the deposition of sediment within it. The small quantity that might settle there would probably be agitated and scattered by the numerous lake steamers in their passage. All accounts agree that, since the first settlement of this region and the navigation of the lakes, no apparent change has taken place in these flats, except where the vessels pass through. There the depth of water appears to have slightly increased. Hence there seems every reason to believe that the channel, when excavated, will prove substantially permanent. As the present appropriation for deepening the channel over the St. Clair flats amounts to only $45,000, it is evident, from the foregoing, that the original intentions of the department cannot be fully carried into effect, and it becomes necessary to adopt a plan of operations upon a diminished scale. I consider it of great importance that, during the first season of operations, a navigable channel should be opened from the deep water of the river to the deep water of the lake, so as to carry the current of the stream and its sedimentary matter entirely through, and afford an improvement which will be of decided advantage to the commerce of the lakes. I would, therefore, propose to adopt a narrower width for the channel and side slopes, in order to give completeness to the work, upon such a scale as the appropriation will allow. I will now present some of the data upon which the above proposition is founded. Mr. Williams, who had charge, under the Buffalo Board of Trade, of the dredging on the St. Clair flats in the summer of 1855, with the government dredging machine, and another of smaller dimensions, reports an excavation from August 1 to October 24 of 18,453 cubic yards, giving an average of less than 220 cubic yards per day. It is hoped that, by judicious management the coming season, an average of at least 250 cubic yards per day may be excavated by each dredging |
