cated and practical engineer, capable of comprehending the magnitude of this subject, I feel myself quite assured that the occasion now offers itself; and I therefore make haste to submit to you my further memoir of my complete plan.

Two centuries before the country west of the Mississippi and the States of Florida and Louisiana came into our possession the French and Spanish commenced the present system of diking. It was at first a temporary expedient to protect from overflow plantations established along the river bank, where the delta lands, from the nature of their creative process by deposit, were the highest. As this foreign population increased, and planting progressed, plantations and their dikes grew together, forming long unbroken lines from the cultivable lands, lowest down the river, so far up as the old creole settlers on it carried their enterprise and planting. So that this great mischief, springing from so small a beginning, when the country was purchased by our government had grown to enormous proportions. It had wholly checked the creative process that was forming in the entire delta basin of the Mississippi new lands, by spreading its yearly flood-waters in overflow its entire length and breadth, depositing its delta sediment.

This foreign element that first colonized along the Mississippi bank knew nothing of the tributaries of this river, from what sources its great volume of creative delta-forming floods came, or the unchanging laws of their cumulative deposits and delta-land formations. From their loins a mixed race has sprung, more distinguished by desire and habit of luxurious ease than by the energies and enterprise of the AngloAmerican, that have since founded great states, and carried civilization to the head-waters of every tributary of the great father of waters.

The problem proposed in my first memoir was intended first to correct the mischief begun by these first colonists and planters on the banks of the Mississippi, by skilfully undoing what they did wrong, by restoring the creative unchanging laws of this river to their office, until the great delta-basin is finished, and the cotton of the world shall be growing where swamp and morass send forth their malaria, and poison the air with pestilence and death.

Having enunciated the plan of reconverting the flood-waters of the Mississippi to their normal use, I now propose my plan of engineering all the waste-waters of the great lakes, that discharge themselves over Niagara Falls, and find their way to the sea through the Gulf of St. Lawrence, so as to feed the upper Mississippi, the Illinois, and Ohio rivers in their low stages, and to give them a fixed minimum supply for navigation during all seasons of drought and scarcity of water.

This problem of hydraulics is not less important than that of controlling the floods of the Mississippi, and has fewer difficulties in the way of its practical solution. It is co-operative with the other. Both are of importance that cannot be overestimated. Vast as the country is over which the engineer must run his surveys and operate all the surplus waters of the lakes, it is so geographized by nature that he has only to trace his levels, calculate his cuttings, make his estimate of costs, and the work is ready for any skilful hand to accomplish. God has made the country so conformably to this plan that it would seemingly contravene His purposes to found great civilization here, longer to neglect it. Lake Superior is the natural feeder of the upper Mississippi. All its surplus waters that leap over the Sault of St. Marie's into Lakes Michigan and Huron, and are needed in low stages of water of that river, could be drawn from the northwest end of that lake into Rum river, one of the principal tributaries of the upper river, above the Falls of St.

Anthony. Lakes Michigan and Huron mingle their waters on the same level. They are the natural feeders of the Illinois river, that has its rise in close neighborhood to Lake Michigan. All their surplus waters that empty through the St. Clair river should be drawn off through the Chicago river into the Illinois.

The surplus waters of Lake Erie that discharge themselves over the Niagara Falls into Lake Ontario should be engineered through the Mahoning into Beaver river, into the Ohio.

Nature opposes no obstacles to these three artificial rivers that with little cost could be created with the capacity required to take the surplus waters from the three great water basins at the points indicated. To so brim them with slack or slow falling water as to make them navigable channels from these lakes to the navigable waters of the larger rivers they are intended to feed, and to keep them permanently navigable at seasons of extremest drought and low water, is the task of the engineer.

To minds unaccustomed to the study of the laws that regulate rivers and fix their channels, the idea would at first suggest itself that the effect of diverting these supplying waters of the lakes into the Mississippi would, by increasing so largely its weight and volume, cause it to overflow its low banks, and in seasons of flood greatly add to its destructive effects on the levees of its lower basin, and make inundations inevitable and uncontrollable.

But, in point of fact, the very reverse of such conclusions would be the result. To clearly apprehend this subject the character of the bed of the Mississippi must be understood. From the lower rapids of the Mississippi, at Keokuk, Iowa, to the mouth of the river, at the Gulf of Mexico, the bottom is an alluvium of changing sands and delta deposits. To increase the volume of water in the bed of such a river accelerates its current in proportion to the quantity and weight of the increase, and, by unchanging laws of hydraulics, deepens its channel. When this increased supply is constant, its effect is to fix a more stable regimen in the bed, and in time to regulate into constancy the shifting, shallower currents that have flowed over changing sand bottoms, without the weight and volume to deepen through the delta sediment a more fixed channel. From the mouth of the Ohio river, where the supplying waters proposed to be drawn from all the lakes into the Mississippi all meet and mingle, the maximum effect of the accelerated current will operate most actively in deepening the channel and more permanently fixing stability in one unchanging bed, to the mouth of the river at the Gulf.

It cannot be doubted that this acceleration of current and increased weight of water will require but few years to bore a deep channel through the bars at the main mouth, and do more to improve navigation into and from the Gulf than any other plan of engineering those constantly growing obstructions to the commerce of the sea from the great supplying west. These bars, under the existing flow of the river, confining all its flood delta waters between dikes and discharging them into the Gulf, are constantly growing, and increasing the difficulties of entering any large draught vessels into the sea.

Deepening the channel by the acceleration of its current and constancy in its increased weight and volume will facilitate my plan of wasteweirs, that is intended to be made coextensive with the heaviest floods, and to control them to such natural use as to waste all their waters above mean rise into the low swamps, morasses, and lagoons, until, by cumulative process, their delta deposits shall raise them to high-water level and convert them from their wastes of desolation and malaria into cot

ton and sugar-growing lands, inexhaustible in fertility and incalculable in wealth.

In another view, this engineering problem is of supreme national importance. It will form great interior and safe lines of communication, eminently necessary for extended military operations in time of war. The last war has taught us the uncertainty of all railway communications for military purposes, and the cost of keeping them open. An enterprising enemy can destroy rail lines as fast as they can be built. What daring raiders cannot do money can. No one can doubt that Jefferson Davis, had his exchequer been less drained for other more important war purposes, could have subsidized the destruction of every mile of railroad within the loyal States. In any great war with any powerful nation hired mercenaries would be found along every mile of our principal roads, and their destruction would be inevitable. It was the destruction of southern railroads and the opening of the Mississippi river that put an end to the rebellion. They were the main sinews of war and the strength of the south.

But navigable rivers and lakes cannot be destroyed, and they must become our main reliance as an invulnerable military power. The engineering problem I have in this way suggested flashed on my mind as a military necessity 35 years ago, when I first saw the extent of our vast lakes. their relation to our great rivers, and the extended geography of a country that would be the supplying region in any great and protracted war. These indestructible interior lines of communication are essentially a military need to secure impregnability to a nation peopling this vast extent of continent.

The history of ancient Egypt would furnish an instructive lesson to the engineers of this day. Its engineers had the audacity to seize the waters of the Nile and subject them to the control of man. Thebes and

Memphis grew up under the skilful and daring engineering that laid hands on the floods of that strange river and built unmatched pyramids in lands their cunning fertilized, to be the mistress cities of the nations of the east. The inspired genius of Egypt's engineers bridled the floods of the Nile, spread their waters through artificial rivers over vast barren territory, fertilized it by their rich delta deposits, and poured into these cities the wealth that founded an empire matchless in power, civilizing a people whose eloquent memorials of mechanical arts are the wonder of the world and the shame of the nineteenth century.

The Nile still flows on discharging its fertilizing delta material into the Mediterranean, where its wealth is wasted, threatening, in time, to obstruct the commerce of the east with Europe. The inspiring genius of engineering decayed with the glory of these cities. The sceptre of art it once swayed is broken, and no skilful hand has yet so welded its fragments as to venture again to try its trident sway on the uncontrolled floods of this river of myths and traditionary gods. But the history of the daring of these ancient engineers has survived the decay of more than 4,000 years. Their imperishable memorials stand round in the pyramids, sphinxes, and granite walls of great reservoirs and artificial rivers, and should startle into energy and activity the slumbering genius of this age to apply the cunning of their hands on like immortal achievements. Nubia and Libya, once fertilized by the delta waters of the Nile, now scorch the feet of the Arab with their burning sands, and the traveller sees desolation stand round where the cotton of ancient Egypt was grown for the looms that wrought fabrics of unmatched perfection, and that have enwrapped for 4,000 years embalmed kings without decay. But it should shame us to know that the floods of the Nile are more

sudden, and that the fall of the river gives them far greater force, than the floods of the Mississippi. Yet they were once subjugated to the skill of Egypt's engineers, and down the bridled waters of the majestic Nile the great granite blocks that were wrought into the pyramids and sphinxes of ancient Egypt were, doubtless, transported. To engineer the floods of the Mississippi is a much easier task. The rain tables, the water-sheds and basins of its tributaries are better geographized for engineering, although more vast in their extent. All that is wanting to make them co-operative in effecting one vast hydraulic, controllable civilizing power, is the genius of daring and enterprise within the scope of possibilities of the thinking, skilful engineer.

Water is the civilizer, power, and wealth of a nation. God has granted it to this continent in fruition of supply and wisdom of distribution, suggestive of empire that shall lead the world and found the highest civilization' attainable by man.

It is not intended in this communication to do more than to outline the principal features of my plan. My convictions of its practicability and economical accomplishment are undoubting. It is national in its purpose, and the magnitude of its importance is incalculable.

It is intended to reclaim and appropriate to use millions of acres of waste lands. It is intended to restore to operation the beneficent law of nature so as to create delta lands. It is intended to open up the navigation of the large interior rivers of Texas and Florida that are now obstructed by bars at their mouths, shutting out their commerce from the sea. It is intended to make the upper Mississippi, the Illinois, and the Ohio rivers navigable at all seasons of drought and scarcity of water, and to extend the commerce of the great lakes to the sea by uninterrupted water communication. It is also intended to form imperishable interior military lines of transportation, essential in offensive or defensive war to economy, safety, and impregnability.

As you, Mr. Secretary, are my proper organ of communication with Congress, I transmit this memoir for your careful consideration, and ask, if you see in it practicability and national importance, that you refer it to that body with such remarks as to you may seem befitting. I am, general, very respectfully, your obedient servant,

B. S. ROBERTS,

Brevet Brigadier General U. S. Army.

Major General J. M. SCHOFIELD,

Secretary of War.

HEADQUARTERS CORPS OF ENGINEERS,

Washington, D. C., February 16, 1869. GENERAL: The resolution of the House of Representatives of the 5th instant referred to this office for report, together with the letter of Brevet Brigadier General B. S. Roberts to the Secretary of War, dated December 29, 1868, which contained a printed copy of his memorial on a plan for reclaiming the waste lands of the lower Mississippi, are returned herewith.

In reference to those portions of General Roberts's papers which touch upon reclaiming the waste lands of the lower Mississippi, i submit a copy of a communication made by me in February, 1866, to General Delafield, at his request, which communication I request may accompany General Roberts's papers when transmitted to the House of Representatives.

In respect to the additional paper of General Roberts, (that of the 29th December, 1868,) it seems to me that it is sufficient to state that the idea of connecting the western rivers with the great lakes by a channel with out locks, through which there shall be a constant flow of water from the lakes, (and that is the substance of this second paper,) is one that has been frequently enunciated. I do not find in General Roberts's paper any new facts bearing upon its benefits, practicability, or cost. Indeed, he does not seem to know that the degree of practicability of such schemes has been tested on the most feasible line, that of the Chicago and Illinois rivers.

By referring to the report to these headquarters of Brevet Major General J. H. Wilson and Mr. William Gooding on the survey of the Illinois river, transmitted to the House of Representatives in January, 1868, and printed, it will be perceived that the cost of such a channel-way, capable of supplying only 4,500 cubic feet of water per second to the Illinois river, would be more than $30,000,000.

General Roberts anticipates great benefit to the alluvial region of the Mississippi by increasing from the lakes the volume of that river during its floods, because, he says, the bottom is alluvion and will be dug out deeper the greater the volume. The bottom is not alluvion but tertiary, or older than the drift, and in this I speak from ascertained facts, not from supposition.

The benefits to be derived from increasing the volume during low water of the upper courses of the western rivers, and the pernicious consequences that would follow upon materially increasing the volume of the lower Mississippi at the flood, have been so clearly pointed out in "The Physics and Hydraulics of the Mississippi river," &c., and in other reports of engineer officers transmitted to Congress and printed, that it is quite unnecessary to do more than refer to them in this general manner. Very respectfully, your obedient servant,

A. A. HUMPHREYS, Brigadier General of Engineers, Commanding.

Major General J. M. SCHOFIELD,

Seeretary of War.

NEW ORLEANS, February 22, 1866. GENERAL: I have received your communication of the 13th instant, enclosing a copy of a "Memoir" of "a plan to reclaim the waste swamps, &c., of the lower Mississippi basin, by a new system of diking, so as to use the delta-making material of the water of the river for this purpose," by Brevet Brigadier General B. S. Roberts, United States army, referred to me for report upon the practicability and expediency of carrying into effect the ideas presented therein, &c.

The plan presented by General Roberts is, in brief, to take from the Mississippi river at high water "a volume of water equal to, or approximating to an equality with, the surplus of flood water over the medium” flood, and allow it to flow over the alluvial lands bordering the river and deposit its sediment upon them.

This would, in his opinion, soon elevate those low lands to a considerable extent, and at no very distant day bring them to about the level of the banks of the river, render them cultivable, and the country healthy.

For the facts and figures which I shall use in this communication I