2d Session.

OVERSLAUGH IN HUDSON RIVER-DELTA OF THE MISSIS

SIPPI.

MAY 4, 1842.

Submitted to the House by Mr. BARNARD, referred to the Committee on Commerce, and ordered to be printed.

BUBEAU OF TOPOGRAPHICAL ENGINEERS,

Washington, April 19, 1842.

SIR: By direction of the Hon. Secretary of War, I send the enclosed views about the improvement of rivers, from Mr. Davis, of Georgia, to your care. The objects of the writer appear to be, to have his views known to Congress and to be printed. He is also desirous that they should be presented by some member from New York, as they treat much of the improvement of the Hudson. They are therefore committed to your care. Very respectfully, sir, your obedient servant,

J. J. ABERT, Col. Corps T. E. Hon. DANIEL D. BARNARD, House of Representatives.

To the honorable the Senate and House of Representatives of the United States:

The undersigned asks leave to make a brief formal proposition to your honorable body for the purpose of improving the navigation at the overslaugh in the Hudson river below Albany,

The place and the obstruction there to navigation and commerce, in Consequence of the collection of silt and sediment, at the exhaustion of the force of the flood tides from the sea against the downward current of the river, at that point, is well known to the country from time immemorial.

The undersigned has been, for many years, bending his mind and observations to such objects, and for devising the best mechanical principle, plan, and system, for the improvement of the navigation at such points and places.

Great, magnificent appropriations have heretofore been thought by Congress as the most sure method of improving bars, harbors, and obstructions in rivers between ports of entry and the sea.

That system, it is believed, has been found by experience to produce less commercial benefits to the country than were anticipated in proportion to the amount of expenditures.

There is some science and natural philosophy in the meeting of the downward current of a river and the upward current of the flood-tides from the ocean, particularly at such point where the force of the uptide becomes exhausted, and recedes back to the sea for a given number of

hours. Where the two powers thus meet, and produce an equilibrium for a given time, "twice in twenty-four hours" continually, the force of the two.currents, where they arrive in equal contact, produce inaction at bottom for a given time, which invites and facilitates the gravitation and lodg ment of fine particles of silt and sediment, when thus intercepted in flowing down a river in time of freshets, and there form a mud and sand shoal, or bar, at the bottom, which, if not attended to in time, becomes an obstruction to commerce and navigation.

It is presumed the question has become settled that it is the constitational province of the General Goverement to improve and facilitate commerce and navigation, by the removal of such obstructions in ports and rivers, in tide-way, between the ocean and a port of entry, like the overslaugh below Albany; and also below Richmond, Virginia; Wilmington, North Carolina; Hartford, Connecticut; Mobile, and so on, at any other similar place, where the commerce may be sufficient to warrant the expense. There are some points known to the undersigned, by examination, such as the "straight channel," below Appalichicola, Florida, (where the Government has expended thirty-six to forty thousand dollars to no purpose,) and also in the river below Darien, and also below Savannah, Georgia, where it would be impossible to apply any remedy, as a judicious expenditure of the public money, owing to collateral causes, arising from divisions of the main volume of the river in the vicinity above, which produces such a wide spread surface and scattered force of the principal stream of the river as to materially weaken its detached force at the point where the improvement would be required. The science and philosophy of deciding on what points of the above character can be improved, and which cannot, is very simple, when properly understood and examined.

The undersigned believes that the overslaugh below Albany is one of that class of obstructions to commerce and navigation which can be removed at a moderate expense by the application of his new invented apparatus, particularly for such objects, and he therefore most respectfully proposes to your honorable body to take the subject into consideration; and if it should be the pleasure of Congress to make an appropriation of five thousand dollars for that purpose, and employ the undersigned to remove the obstruction and deepen the channel at the said overslaugh, he will proceed, at any time, to the construction of his apparatus, of sufficient size and strength to answer for that place.

The money to be set apart, at the control of the President of the United States, in the hands of the Secretary of the Treasury, and no bill to be paid for materials, work, or labor done by direction and superintendence of the undersigned, unless approved with his signature at bottom.

The channel there would require to be deepened, so as to give seven to eight feet water during a low river in the summer and fall; and the construction of the apparatus of that size, with a submarine wheel of eight feet diameter, and the connecting parts of ploughs, scoops, &c., is believed, would not cost, in New York, over $2,000; and the balance of $3,000 would cover the hire of a steamboat of sufficient size, labor, and contingencies to perform the work, which should, if ready, be executed soon af ter the spring freshets are usually over in the Hudson river-say in the month of June-so that the country may have the benefit of the navigation during the balance of the year, until the river becomes closed by ice.

When ready for operation, the channel can be swept out in three or four

weeks, with the apparatus and the ebb-tides, sufficient to give eight feet water in the channel, and make it of sufficient width, which is all that would be required at that place.

The apparatus to belong to the Government, and to be housed near the overslaugh from the sun and weather, so as to be always at hand in case it should be wanted in future to sweep out the channel again; which may be required (at a small expense in that case) once every two or three years, from the collection of new matter and sediment coming down the river, during spring freshets, before it may get so bad again to navigation. The undersigned has become convinced, by long experience in matters of that sort upon the sea-coast, from Maine to Louisiana, that the above principle and plan of his apparatus is the only judicious, cheap system for such improvements of the navigation in tide waters which can be adopted and patronized by the General Government, at such places; and he is now willing, on his part, to devote the whole of his time and services to begin at the overslaugh, if patronized by your honorable body-his expenses of travel and board, whilst preparing the apparatus and executing the whole work to be paid out of the appropriation, but to receive nothing for his services or patent right, unless he reduces his system to a successful operation, which could then be applied to other similar places, to be designated by Congress; and in that case, then the Government to pay the undersigned such an amount for his services and patent right as may be deemed just and reasonable.

The undersigned don't want the Government money any further than he can render an equivalent commercial benefit to the country for it. All which is respectfully submitted.

W. B. DAVIS.

To the honorable the Senate and House of Representatives of the United States.

The undersigned presented to your honorable body, through the Hon. Jno. Moore, of Louisiana, in August last, a proposition and new invented model and plan for deepening the ship channel over the bar at the mouth of the Mississippi. No action on that subject was deemed by the committee as coming within the business of the extra session; since which time the undersigned has visited New Orleans and the mouth of the river, for the purpose of obtaining more definite information in relation to the object of deepening the said bar for heavy shipping, in order that more correct data might be obtained for the information of your honorable body and the undersigned, either in pursuing or abandoning the aforesaid proposition; and he now asks leave to make the following report:

First. Ships, at this time, are towed out to sea from New Orleans, through the main channel of the bar, at the southwest psss, drawing sixteen feet water, with a cargo of 2,836 bales cotton, which was the cargo and draft of the ship Corsair, recently towed to sea by the steam tow boat Lyon, on board of which was the undersigned, who particularly noticed the soundings by the man at the lead across the bar, over which the said ship proceeded to sea without any delay, difficulty, or danger; and she is

a ship of good model and proportionment for navigating the Atlantic to Liverpool, where she was bound.

Ships of similar burden, and even larger, are passing in and out to sea, over the said bar, at this time, almost daily.

Second. The bar at the southwest pass (as well as the bars at all the other outlets of the Mississippi) are composed of soft silt mud, formed entirely from the fine drift particles of that portion of the great mass of sediment and alluvial washings of the vast interior of the country, which are too light and buoyant to settle to the bottom, even in the long course of the strong downward current of such an immense river, until it reaches, and enters into contact with, the other strong and powerful current (in connexion with the tides) from the gulf stream, which produces a counteracting ingress power and formidable obstacle to the outward bound current of the river.

At the point where these two powers (or currents) become exhausted, for any given time, or rather short vibrating periods of time, by the action of the tides upon the under part of the current of the river, and thereby reducing the lower part of the volume of the outward bound current to an equilibrium of power, or, in other words, thereby producing still waters at the bottom, during certain hours of the flow of the tides, it is there, and at such point more especially, that gravitation will take place of the aforesaid drift-mud and buoyant portion of the silt and sediment of the river; which, before, has not met with any place sufficiently void of an impelling motion onward, by the current of the river, to become at rest and settle into a soft mud-drift at bottom, which may be compared, as to the principle of formation, to the principle of natural philosophy by which snow is thrown into drifts and banks.

The foregoing is a brief outline of the two natural causes, and the composition of the soft mud bars at all the different mouths of the Mississippi river; and the one at the southwest pass is so much like pulp or soft blubber at the bottom of the main channel that a ship bound out, drawing 17 or 18 feet, has been towed to sea, at high water, dragging two feet through the above described soft bottom; which having, in some instances, stopped her head way two or three times for a few minutes, it was ascertained, by soundings across her stern, that the track she made through the soft mud drift at bottom, will close up immediately in the rear, which proves the bottom of the channel to be more like the composition of soft soap than a stiff mud bank.

Third. The tides, when uninfluenced by the wind, may be stated at eighteen inches perpendicular rise and fall on the bar, and the average depth, at high water, sixteen feet, for ships of that draft to pass out to sea with safety.

There is no probability or present danger that there will ever be less, which is deemed amply sufficient for all commercial purposes, especially when the soft, elastic nature and composition of two or three feet of the bottom of the channel is taken into view; which, in case of necessity, of an extra large ship, (which seldom happens,) can be pressed through without danger, at high water, with the assistance of a steam tow boat, which are employed there for towing ships to sea.

In regard to naval purposes, it is not presumed that the General Government would desire to deepen the bar at the south west pass for that object, as Pensacola is already established for that purpose, so near at hand.

In addition to this view of that part of the subject, it has been ascertained by the undersigned that a large portion of the citizens of New Orléans consider the bars at the mouths of the river, in their present commercial capacity for merchant ships only, would prove to be their best forts for the protection of the city from the naval ships of an enemy in time of war, which, it must be admitted, is not a bad idea.

Fourth. There is, at this time, only about twelve feet average, at common tides, on the bar at the northeast pass, which was formerly the deepest outlet, but the prospect is changing more and more in favor of increasing the volume of water through the southwest pass, which will tend to increase the present depth of water on that bar, without any artificial aid. This fact is clearly demonstrable from an observation of the main river at that point, where it is all in one body, at the head of the passes, and there divides off into parts, each to seek its own unison with the level of the sea. At the above point, the largest portion or volume of the main river is directed, by a partial bend and inclination, next above the head of the passes, so as to throw the greatest weight and force of the main current upon the western side of the middle of the river; and which is gradually increasing the volume and power into the chops of the head of the southwest pass, and is forming a mud shoal, from the point of marsh, at the head of said pass, diagonally up stream, and partially across the opening which forms the head of the northeast pass, and all the other smaller passes in that direction.

This will render the current of those eastern outlets less active, and induce an increased accumulation of sediment at the bottom of those channels, which are formed obstructively to the force and velocity of the current, in consequence of being more crooked and incumbered with islands, mud lumps, and shoals; whilst, at the same time, the southwest pass, from its head to the bar, being almost perfectly straight, and a great splendid volume of active water, with a powerful current, pressing down in a straight direction, without any obstruction, to force its own way into the sea across the bar, must, and will most assuredly, continue to operate still more in favor of heavy shipping at that outlet.

For the foregoing reasons, the undersigned is forced to the conclusion, from his own ocular senses and impartial judgment, that the necessity of deepening the bar at the southwest pass or at the northeast pass of the Mississippi, by the General Government, would not warrant the expense of the experiment.

Consequently, the undersigned finds nothing which he can conscientiously recommend to your honorable body, to cause to be done for the improvement, safety, and facility of commercial shipping, to pass in and out of the Mississippi river, except the construction of a wooden octagon light-house, at the south point, at the mouth of the south pass, in place of the one recently fell down there, and the placing of buoys on the bars of the southwest and northeast outlets; which, the collector of the port of New Orleans informed the undersigned, are now in treaty of contract, to be accomplished through him and the Secretary of the Treasury.

Fifth. When the flood tide makes in, the course is along the bottom of the channel; and although assisted by the eddy current and proximity of the gulf stream until high water, yet it is too weak at any stage, during the time of flowing in, to counteract the immense force of the whole outward volume of the river.