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all the items of intelligence appertaining to western commerce would be attended with great labor, trouble and expense, far greater than I have had it my power to bestow, either personally or by proxy.

In the document referred to a brief abstract merely has been attempted, with the view of exhibiting the more prominent features of the subject. The sources whence the information has been derived are duly recognized and acknowledged in the document.

With respect to the utility and importance of the several lines of communication-viz: of rivers, canals and railroads-in a military point of view, and the facilities, despatch and cost with which troops and military supplies of all kinds can be conveyed from point to point, or from one commercial depot to another, they may be readily inferred from the tables contained in the document referred to, in which the distances between important points are exhibited in miles, the duration of the transit for freights and for passengers over these distances, and the ordinary cost of conveyance for freights and passengers through the same distances are exhibited.

Respectfully submitted,

S. H. LONG, Lieut. Col. Top. Eng., Late Superintendent Western River Improvements. Colonel J. J. ABERT, Chief Topographical Engineers, Washington, D. C.

P. S.-Letters from Captain Johnson, dated on the 31st ultimo, inform me that no favorable changes in the width and depth of the channel at and near the mouth of the Southwest Pass, produced by the operations of Messrs. Craig and Rightor, were perceptible at that date. Also that the smallpox had broken out among their laborers, and that they had been compelled to repair with their pile boat, &c., to New Orleans in quest of medical aid.

S. H. LONG, United States Army.



Contract-Charles Gregoire, president, with S. H. Long.

This agreement, made between the president of the Dubuque Harbor Company of the first part, and the government of the United States of the second part, witnesseth: That the said party of the first part agrees to construct a causeway leading in a direction south 653° east from the foot of First street, in the city of Dubuque, to the point "A," on the river side of the outer island, immediately below the main outlet of Dubuque harbor, said causeway to be surmounted by a roadway 30 feet wide, to be elevated at least 3 feet above extreme high water of the river, to be furnished with a slope of 1 in 6 on its upper side, the whole to be completed in one year from the date hereof, unless prevented by the prevalence of high water in the river.

And it is further agreed that so much of the material for the causeway shall be taken from the bottom and sides of the channel leading from the main river, through waples cut to the slough or basin, whenever said channel is touched by the causeway, as will leave the channel 200 feet wide, or of a width and depth not less than what exists at present. The position and direction of the causeway to be determined by an officer or agent of the United States, and the work carried on to completion in accordance with such determination and plans as approved by him.

In consideration of the work done on said causeway, and after the same shall have been completed, the United States agree to pay to the said party of the first part the balance of appropriation remaining on hand, after all just liabilities incurred by the United States are paid. Said balance to be paid by the United States, through their agent, after the agent, from inspection, shall have ascertained that all the provisions of this agreement, as regards the construction of the causeway, shall have been fulfilled by said party of the first part.

And it is further agreed that any expense incurred by the party of the first part in the construction of the causeway over and above the balance of appropriation paid to them shall not constitute any grounds for a claim against the United States, or against any further appropriation which may be made by Congress for the further improvement of the harbor of Dubuque. And said causeway shall remain a free and open highway.

Done in triplicate, this 6th of September, 1856.

CHARLES GREGOIRE, President Dubuque Ilarbor Company. S. H. LONG, U. S. A., Superintendent Western River Improvements.


Colonel Long to Hon. G. W. Jones.

LOUISVILLE, December 22, 1856.

DEAR SIR: Having been apprised that sundry respectable citizens of Dubuque are desirous of some expression of my views in reference to the capabilities and importance of Dubuque harbor, I take leave briefly to offer, through you, some of my convictions on these interesting topics.

The site of the harbor is on the westerly side of the Upper Mississippi, in latitude about 421° north, and is effectually landlocked and separated from the main river by a cluster of islands, which shield it from the encroachments of floating ice and other drift in all stages of the river, except in extraordinary floods, when the overflow covers the islands to the depth of a few feet only. During the periods of such overflow the influx of drift of all sorts may readily be prevented by the construction of levees of moderate height along the exterior margin of the outer island.

The present harbor or basin embraces an area of between two and three acres, in which there is a low water depth of about four feet, and is sufficiently capacious to accommodate some eight or ten steamers of ordinary dimensions, but is rendered inaccessible to such craft during the low stages of the river for want of a navigable channel connecting the harbor with the river.

By removing that portion of Bass island situated between Barney's cut and the line of the causeway in progress of construction by the Dubuque Harbor Company, and by dredging the inner and outer sloughs, including the site of Bass island and the main outlet of the harbor, to the depth of four feet below the surface of extreme low water, the harbor may readily be enlarged to an area of more than twenty acres, and to a capacity sufficient to accommodate more than one hundred steamers with safe protection during the period of the winter frosts.

The materials excavated by removing Bass island, dredging, &c., may be employed to great advantage in the formation of levees, terraces, causeways, &c., of earth work upon the islands, across the sloughs, and around the harbor, by means of which not only will the capacity of the harbor be enlarged, but the facilities for business transactions connected with it will be incalculably multiplied.

The number of steamers now plying on the Mississippi above Rock island, during the season of navigation, may be computed at about twenty, and will, in all likelihood, be increased to at least one hundred in the course of eight or ten years, most of which may readily and conveniently find and occupy a safe and commodious harbor at Dubuque.

The importance of this point is greatly enhanced from the fact that it has been made the terminus of the Great Central Railroad of Illinois on the Upper Mississippi; also from the consideration that other railroads, leading southward, westward, and northwestward, which are not merely in project, but some of them actually commenced, diverge from the same point, and lead through a region of incalculable wealth in an agricultural and mineral point of view.

The population of Dubuque amounts at this time to about eight thousand inhabitants, and is rapidly increasing at the rate, probably, of more than twenty per cent. yearly, so that in less than five years it will amount to more than double that number.

To the best of my knowledge and belief, there is no other position on the Upper Mississippi that presents equal facilities for the construction of a capacious, safe, convenient, and commodious harbor in any of these respects comparable to those afforded at Dubuque.




Colonel Long to Colonel Abert.

The means employed consisted of a substantial drill boat worked by steam; of a large decked scow, for the reception and removal of the broken fragments of blasted rock; of a quarter boat for the accommodation of the working party, and of a yawl, and sundry other items of craft and appliances, procured by the contractor for the execution of the work of his contract

The principal machinery used in connexion with the craft consisted of a steam engine of six horse power, employed in working a drill weighing between 2,500 and 3,000 pounds.

The drill is composed of two pieces, viz: a cutter or bit of cast steel highly tempered, weighing about fifty pounds, and a rod or stem of wrought iron weighing upwards of 2,000 pounds, (the rod and bit, together, weighing upwards of 2,500 pounds, as before stated;) these two parts being suitably connected together by means of a socket attached to the rod, a tenon to the bit and a key passing through both. The strokes made by the drill number fifty per minute; the drop of the same is twenty-two inches; the hole made or bored by the same is four and a quarter inches in diameter, and the time required for boring a hole four and a quarter inches in diameter and four to five feet deep is sixty minutes or one hour. The blast is effected by the use of about ten pounds of powder, properly enclosed in cannisters with tubes. The average quantity of stony fragments displaced at every blast is at least four cubic yards.

When reduced to fragments, as above, the stone is raised by means of a crane and grapples and deposited on the decked scows, before mentioned, and conveyed to positions where the agent has deemed it expedient to orm wing dams for the purpose of preventing the passage of water currents leading athwart the improved channel.

NOTE.-Doubts are entertained with respect to the stability of structures of this sort at the place where they are contemplated to be formed. Ice and other drift brought down by the rapid current of the Mississippi will be likely to demolish and sweep them from their foundations.

The means at present employed for the removal and deposition of the broken fragments are far from being adequate for this purpose. Additional means are now in preparation, and are expected to be ready for use at an early future date.

A new method of operation, which has already been partially tested by the contractor and found remarkably efficient, is about to be adopted in the further prosecution of the work.

This mode contemplates the employment of a steam engine of ten horse power for the purpose of working a massive slicer or cleaver armed at the cutting end with a cuspidated cutter of cast steel, the whole instrument weighing about 3,000 pounds. The entire length

of the cleaver is to be about twenty feet, and its rise and drop about fifteen feet; its movements are to be regulated between cheek timbers, &c., similar to those of the ram, &c., of a pile driver.

It is said that the means and mode of operation above considered have been found highly efficient and useful, at an expense comparatively moderate, in cleaving rocks at Albany, New York, lying six or eight feet below the surface of the water, and that similar benefits have resulted from their application to the rock excavations made for the canal at the Sault de Ste. Marie.

Agent Floyd appears confident of the beneficial results likely to spring from this method of operation, and from the best lights I can get in relation to the subject, I am inclined to concur in the same views.



J. H. Hager to Agent Floyd.

KEOKUK, IOWA, October 28, 1856.

SIR: I regret to find, by your note of yesterday, that by inability during the present season to get out 1,500 yards of rock per month has given apparent cause to Colonel Long to complain that I have not complied with my contract.

As you are aware, the difficulty of procuring hands to caulk my boats, after all other preparations had been made, as early as it was supposed the stage of water would allow, prevented me from getting to work till early in August, and of course the work for that month did not amount to the required quantity.

The excavation in September was going on rapidly up to the 16th, when a cold spell of weather set in, which lasted until the 5th of October. During this time the cold was so unusually severe, for the season, that it was with great difficulty men could be induced to go into the water at all, and after they were in they could work to very little purpose. I procured water-proof boots for them, but this did not obviate the difficulty, and the result was, that it was impossible to get out the 1,500 yards during either month. The same sort of weather set in again, with heavy rains and a rise in the river, on the 20th October, and has continued until this date.

These circumstances will, I trust, be considered a sufficient excuse for what would otherwise seem to be a disregard of the obligations of the contract; and I would be much obliged if you would communicate to Colonel Long a copy of this explanation.


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