DOCUMENT No. 5.

Agent Floyd to Colonel Long.

KEJKUK, Iowa, October 30, 1856.

SIR: I herewith send you a copy of a note addressed by me to J. H. Hager, esq., contractor for the "improvement of the Rock River and Des Moines rapids," and also a copy of his reply. I am fully conscious of the difficulties he had to encounter in obtaining caulkers, and I informed you of it at the time; and I recollect, also, of hindrance by bad weather. But I am confident that Mr. Hager's greatest misfortune has been from the neglect, indolence, and bad management of his manager. In the occasional absence of Mr. Hager, I urged, in every way, more energy from his manager, but the result is as you have been informed.

The weather is now becoming too cold for work, and but little more may be expected this season; and there is, also, now a swell in the river from the late very severe storms, which, if it continues, will greatly impede the efficiency of the work. I think that the contractor is entirely disposed to fulfil his contract; and that he would undoubtedly do so another season, provided it should not be determined by the bureau that he has forfeited his contract.

J. G. FLOYD.

DOCUMENT No. 6.

Colonel Long to Hon. H. Marshall.

LOUISVILLE, December 18, 1856.

SIR: At the instance of Captain J. R. Hamilton, an experienced falls pilot, who had been requested by sundry pilots, captains, and other commercial men, to remove a formidable obstruction from the main low water channel of the Ohio, at a point about 250 yards below the mouth of the Louisville and Portland canal, I am induced to offer the following remarks on the nature and character of the obstruction removed and on the cost of removing it.

The obstruction was occasioned by the wreck of the steamer Magnolia on the rocks at the point mentioned, the channel at which is only about one hundred feet wide. The boat, when wrecked, assumed a position athwart the channel, its stem protruding some fifty or sixty feet into the channel, and endangering the passage of boats between it and the shore of said island. Three or more steamers had been seriously injured in passing around the wreck, and at least three flat-boats were sunk by collisions with the wreck.

Captain Hamilton appears to have been encouraged and induced, by persons deeply interested in the navigation of this portion of the Ohio, to undertake the removal of the wreck, which he has successfully accomplished at very considerable cost. His account for expenditures

incurred amounts to $559 91, which, in view of the circumstances of the case, the formidable character of the obstruction, and especially of the inadequacy of the means and apparatus that must be relied on for effecting the removal, may fairly be regarded as a reasonable expenditure.

I take leave to add that there remains in my possession a small balance of the appropriation of 1852, for "the improvement of the Ohio, including Cumberland dam," out of which, with the approval of the honorable Secretary of War, the account of Captain Hamilton may be liquidated.

S. H. LONG.

DOCUMENT No. 7.

Colonel Long to Hon. J. Guthrie.

OFFICE WESTERN RIVER IMPROVEMENTS,

Louisville, July 18, 1856.

SIR: I have the honor to be in receipt of your favor of the 10th instant, relating to surveys for a new set of locks and for the enlargement, &c., contemplated for the Louisville and Portland canal.

In a former letter I communicated sundry views and suggestions in relation to the canal, which I take leave to explain more clearly and intelligibly on this occasion, and in the following order:

Of the locks at the lower end of the canal.

1. It is proposed to construct a single lock at the lower end of the canal, trending downward from its head, somewhat more nearly in the direction of the river than the existing series of locks, for the purpose of rendering the ingress and egress of large boats, in connexion with the river below, more safe and easy.

2. In order to render the locks passable for the largest boat navigating the Ohio, the length of its chamber must be 360 feet and its width 75 feet in the clear, those being, as nearly as I can ascertain, the length and width of the steamer Eclipse.

3. The lift of the lock, in ordinary low water, must be at least 25 feet, this dimension being equivalent to the aggregate fall of the Ohio between the head and foot of the canal.

4. The floor of the lock chamber, or rather the tops of the mitre sills, should be at least five feet below the surface of ordinary low. water, in order to admit the passage of boats drawing at least five feet.

5. The height of the lock walls should be about three feet greater than that of the highest surface water both of the lock and of the canal, at the stage (10 feet above ordinary low water) when the canal becomes useless by reason of the greater facilities for navigation presented by the main river. Hence the height of the walls should embrace the following subordinate dimensions, viz: five feet for draught of boats, twenty-five feet for lift, and three feet in order that the

guards of boats may never rise above and lodge upon the copings of the walls; thus making the aggregate height of the lock walls above the mitre sills of the lock forty-three feet.

6. The lock chamber should be furnished with four sets of gates, all of the same size, viz: one set near the head and one at the tail of the lock; besides which there should be two intermediate sets, for the purpose of rendering the lock divisable into three distinct chambers, of the following different lengths, viz: from the head to the first intermediate gate 160 feet, from the head to the second intermediate gate 260 feet, and from the head to the tail gate 360 feet.

7. By this arrangement boats and other craft of small dimensions may be accommodated in the first chamber; boats, &c., of a larger size in the second chamber, and boats of the largest class in the third chamber. The arguments in support of these arrangements are as follows:

First. The detention for lockage will be materially reduced, which is also true in regard to the quantity of water required for lockage. In view of the variety of craft likely to pass through the lock, the detention for lockage and the lockage water required will probably be less than half that would be expended without the intermediate lock gates.

Second. The quantity of silt or sedimentary deposits brought into the canal and lock would also be less in the same proportion by adopting the arrangement in question. Accordingly the balance resulting in favor of the arrangement, on the score of economy, would fairly entitle the same to a preference over any arrangement that could be adopted, without the use of one or more sets of intermediate gates.

8. The height of the gates above the mitre sills should be about forty-one feet, or two feet less than that of the lock walls. The width of each leaf will be about thirty-nine feet. Each leaf may traverse on its own quoin-post, being effectually sustained by means of iron stays, with screw stretchers passing from the head of the quoin-post to points at or near the lower end of the toe-post. In this way the toe of the gate may readily be elevated or depressed at pleasure, and made to swing clear of the lock floor without the intervention of circular rails and friction rollers.

9. The chambers may be filled or emptied through wickets, or scuppers with fly-gates, situated in each leaf near the bottom of the gates, or by side culverts, &c., in the lock walls, as usual.

10. N. B.-The main reason of making the head gate of the lock of the same height as that of the other gates thereof is, that in filling a lock of so great a lift the jets of water from scuppers situated twentyfive feet above the surface water of the lock (which would be the case in ordinary low water) would unavoidably be poured on the decks of the boat, either at its bow or stern, and occasion serious inconvenience and injury on board, which would not be the case when the jets are made below the surface of low water in the lock.

Of the canal enlargement.

11. Assuming 75 feet as the width of the lock chamber, the width of the water way of the canal should be about 100 feet. This width would leavefor windage on both sides of a boat 75 feet wide, 25 feet, or 12 feet on each side, which I regard as a suitable allowance merely for a boat of that width, the movements of which, in passing through the canal, ought to be regulated by her rudder. According to the facilities for propelling a boat through the canal by the use of steam, will be the speed of her movements. In a canal whose width does not exceed that of the lock chamber, the movements of the boat must, unavoidably, be retarded, and sometimes entirely arrested by frequent impacts against the sides of the canal.

12. The enlargement should be made on the northerly 'side of the canal, in order that the excavations required therefor may be applied to the formation of an embankment and causey on that side, rising to an elevation at least two feet above the surface of the highest known flood. This would give for the height of the embankment above low water 42 feet at the head of the canal, and 67 feet at the foot of the canal.

13. The side walls of the canal should rise to the level of the lock walls, viz: 43 feet above the mitresills of the lock, or 18 feet above the bottom of the canal. At this height the tops of the walls would rise above the guards of a boat at the highest stage of water for canal navigation.

14. The slopes of the embankment should rise from the summit of the canal and lock walls, at the rate of 1 to 1, quite to the grade or roadway at the top of the embankment.

15. At least two passing places should be provided for on the southerly side of the canal, in addition to that at the head of the lock, each of which should have a width equal, or nearly so, to the width of the canal. One of these should be situated, if practicable, at the point most suitable for the pivot drawbridge.

16. The drawbridge should traverse horizontally, on a suitable stone pier erected for its support, about midway of the line between the canal and the passing place. The draw should rest upon a properly constructed turning table and platform, covering the head of the pier. Thus situated, one end of the draw would span the canal, while the other would span the passing place; and, being in itself equi-librated on the platform and top of the pier, may readily be made to traverse back and forth on its pintle in a manner to admit the passage of one or two boats at once, as occasion may require.

Of the guard gate and its piers, &c.

17. The guard gate should be located in the basin at the head of the canal. Its piers and the guard gate should rise at least 42 feet above the surface of ordinary low water at their base, and should be arranged in such a manner that the shore pier head may serve as a boom post for the shore end of a boom, and the river pier head as

post for the other end of the boom, the former being situated further up the river than the latter, in order to afford the requisite obliquity to the boom when stretched from one pier head to the other. The shore pier should be connected to the shore by a wing wall of the same height as that of the piers and gates. In like manner the river pier should be connected to the embankment or causey by a wall, all being of a uniform height.

18. The gates should consist of two leaves to each, the lower leaf rising about 20 feet above the mitre sills, and the upper leaf rising about 27 feet above the top of the lower leaf. The lower leaves are designed to be short, whenever there may be occasion to employ the canal for any purpose whatever, while the upper leaves are to subserve the purpose of stopping the ingress of water into the canal space whenever a freshet rising above the lower set of leaves may occur.

19. The boom should be of a coffer form, about fifteen feet wide, one hundred feet long, and five or six feet deep, constructed somewhat after the manner of a flat-boat, square at both ends. Such a boom may readily be floated to the heads of the piers, and occupy a position oblique to impinging currents, drift, &c., and prevent the accumulation of drift, &c., between the piers and above the guard gates whenever the higher stages of the river render the canal useless. On the subsidence of such freshets the boom may readily be withdrawn and moored in some suitable place, the guard gates thrown open, and the canal made free for the passage of boats.

20. Thus fortified and protected by the high embankment through the whole extent of the canal on its northerly side, and by the guard gates, piers and wing walls at its head, the canal will be exempt from overflows by floods loaded with drift, suspended silt, &c., and secure from the deposition of floating materials and sedimentary deposits. Inundations of the entire canal space in rear of the embankment and below the guard gate will, of course, occur in very high freshets, but such overflows will be occasioned exclusively by back water entering from below the canal after having parted from its drift and deposited its silt to such an extent as will exempt the canal from annoyances of this character.

21. The views attempted to be sustained by the foregoing remarks seem, in a few instances, to be somewhat in conflict with some of the suggestions contained in your letter. I have deemed it expedient to present, in a more intelligible form, sundry leading objects, and the reasons therefor, as contemplated in my hurried letter of the 16th ultimo.

22. The whole is respectfully submitted to your arbitrament with the desire of obtaining your concurrence, or, rather, your decision, in regard to their relevancy or otherwise.

23. I have had a brief interview with the president and directors of the Louisville and Portland Canal Company, who concur in the propriety of commencing the surveys as soon as practicable, by wings at and near the foot of the present canal, for the purpose of ascertaining the position, depth below the surface, and configuration of the rocks underlying the canal at that point. The developments expected