The Mississippi Valley: its physical geography, including sketches of the topography, botany, climate, geology and mineral resources ... Illustrated by maps and sections

Front matter

THE MISSISSIPPI VALLEY: ITS PHYSICAL GEOGRAPHY. THE MISSISSIPPI VALLEY: ITS PHYSICAL GEOGRAPHY, INCLUDING SKETCHES OF THE TOPOGRAPHY, BOTANY, CLIMATE, GEOLOGY, AND MINERAL RESOURCES ; AND OF THE PROGRESS OF DEVELOPMENT IN POPULATION AND MATERIAL WEALTH. BY J. W. FOSTER, LL.D., PRESIDENT OF THE AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE JOINT-AUTHOR OF " FOSTER AND WHITNEY'S REPORT ON THE GEOLOGY OF THE LAKE SUPERIOR REGION;" LECTURER ON PHYSICAL GEOGRAPHY AND COGNATE SCIENCES IN THE UNIVERSITY OF CHICAGO, ETC, ETC. Illustrated by Maps and Sections. uReru?n cognoscere causasP CHICAGO: S. C. GRIGGS AND COMPANY. LONDON: TRUBNER & CO 1S69. Entered according to Act of Congress, in the year 1869, By S. C. GRIGGS AND CO., In the Clerk's Office of the District Court of the Northern District of Illinois. CHURCH, GOODMAN AND DONNELLEY, PRINTERS, CHICAGO. JOHN CONAHAN, STEREOTYFER.

Preface

. Having devoted many years to explorations in different parts of the Mississippi Valley, and to the study of its soil, climate, and resources — mineral and agricultural, — and having been a witness, in part, of the gigantic strides which have been made during the lifetime of a generation, in those arts which contribute so essentially to the comforts and conveniences of man; — I propose to describe, in a comprehensive form, the Physical Geography of this wonderful region, and particularly of that portion which lies west of the great dividing line — the Mississippi River. Already this valley con tains a majority of the people of the United States; and the developments which are now going on to brinoit into close commercial relations with the minings regions of the Ultra-montane and Pacific States, and with the markets of the Orient, will add vastly to its resources, and to its commanding position as a part of the Great Republic. VI

PREFACE.

. With regard to the capacities of the region lying between the eastern rim of the Great Basin and the Missouri River, and known as the Plains, the vaguest ideas prevail. Some theorists, little versed in the laws of climatology, and over-sanguine as to the expansibility of our country, have anticipated the time when population would flow, in an un broken wave, to the base of the Rocky Mountains; while others, more cautious, drawing their conclusion from sources not less erroneous, have been disposed to regard this region as an irreclaimable desert. It is neither. While God has doomed certain portions of the surface to everlasting sterility, the greater portion will forever afford vast ranges for pasturage; and much of it, under a suitable sys tem of irrigation, can be reclaimed and made to rival the ancient fruitfulness of the valleys of the Tigris and Euphrates.

The phenomena of forest-growth, of grassy plains, and arid wastes, it is believed, result from laws as constant and harmonious in their opera tion as those which regulate the planetary move ments. It was with a view of illustrating the gradations between the forest, prairie, and desert ; the varying conditions of temperature and moisture, and their effects in determining the range of those plants cultivated for food; and, at the same time, to trace

PREFACE.

. VII the character of the fundamental rocks over the whole of this region, pointing out the mode ol occurrence of those ores and minerals useful in the arts; and, finally, to trace the colonization of this region from its feeble beginnings to its present magnificent proportions; that this work was under taken. With the multiplication of observations — meteorological and geological, — it may be found necessary to modify some of the views herein ex pressed; and the most that I can hope is, that they may prove to be in the right direction. No writer at this day upon physical geography can justly ignore the great name of Humboldt. He explored nearly the whole realm of nature, and investigated her laws with a patient industry, and in a philosophical spirit, which have seldom been approached. He first reduced meteorology to the regular and consistent form of a science, when he mapped the lines of equal temperature, thus show ing the distribution of heat over the seasons, and, in connection with the hygrometric state of the atmosphere, and the precipitation of rain, traced their effects upon the geographical range of plants.

From confusion and uncertainty, he evoked order and harmony; out of materials apparently incon gruous and misshapen, he erected a temple to science, proportionate alike in its outlines and in

PREFACE.

. its several parts. He is emphatically the father of the science known as Physical Geography. The scientific expeditions fitted out by the Gov ernment to determine the most practicable routes for railways between the Mississippi Valley and the Pacific Coast, have given us an insight into a vast region which before was almost a tei'ra incognita. The results are embodied in a series of volumes, not accessible to the general reader, even if he had the time to peruse them, known as " The Pacific Railroad Surveys." The earlier expeditions of Lewis and Clarke, Pike, Long, Fremont, Wilkes, Stansbury, and others, gave us general outlines of the physical geography; and yet, with the combined results of these observers, and of those who have subsequently become connected with the various mining enterprises, much is yet to be determined in every branch of natural history.

To Messrs. Meek and Hayden the public are indebted for valuable contributions to the geology of the eastern slope of the Rocky Mountains. The results of the Geological Survey of Califor nia, under the charge of Prof. J. D. Whitney, afford us a key to unlock the hidden mysteries of that complicated region; and it is to be regretted that so important a work has been suspended. In the year 1819, a regular series of meteorologi cal observations was instituted at the various Mili-

PREFACE.

. IX tary Posts of the United States, under the authority of the Secretary of War, which has been continued to the present time. In 1857, these observations, together with those which had been made at other points by competent observers, were tabulated and brought out by Mr. Lorin Blodget, in a work en titled " The Climatology of the United States." This work contains a vast amount of information, and is the foundation of most of our discussions in reference to the lines of temperature, the distribution of rain, and the prevalent direction of winds in the United States. But a work so thorough, must necessarily be encumbered with minute details, so that the generalizations are not presented in so compendious a form as to be appreciable by the cursory reader, nor are they, in all instances, carried to their legitimate results.

The work is like an arsenal, to which the soldier resorts to equip himself with an armor suited to the actual conflict. It is to be regretted that the Smithsonian Insti tution, which has been made the repository of these observations continued up to the present time, has not communicated to the world the tabulated results. These results, it is hardly necessary to sa}', are of great importance in enabling us to determine the varying fertility of the Continent. Prof. Asa Gray, in Silliman's Journal, 1857 and 1859, and Dr. J. G. Cooper, in the Patent X

PREFACE.

. Office Report for 1860, have contributed valuable information on the geographical range ot the for est-trees of North America; and it is to Sir John Richardson that we are almost entirely indebted for our knowledge of the climatology, in connec tion with the botany, of the circumpolar region of this Continent. The work of Humphreys and Abbot, on " The Physics and Hydraulics of the Mississippi River," is of the very highest scientific interest. Principles the most elaborate, are patiently wrought out, and the results are clearly enunciated. From these demonstrations, it is evident that the views which formerly prevailed as to the extent of the delta, and the effects of fluviatile action upon the bed and enclosing banks of that river, were not understood. This work, — which, with much distrust, I now submit to the public, — is not intended to be a purely scientific treatise.

The severity of style and rigor of deduction which characterize such works, have been purposely avoided. I have attempted rather to present a series of graphic sketches of the great phenomena of the region under considera tion, in a form which should interest and instruct the general reader, and, at the same time, to explain those natural laws to whose operation these phe nomena are due. In preparing it for the press, I have been oppressed by a double fear, — lest, while

PREFACE.

. XI I might render it too abstruse for the compre hension of the general reader, at the same time, the specialties were not sufficiently exact to satisfy the requirements of those, who brought to the investigation of these subjects a purely scientific spirit. These details render science repellent to those who have not acquired a special knowledge of the ele ments on which it is based. It is believed, how ever, that generalizations may be set forth in a man ner to interest and instruct the ordinary reader. In discussing the operation of natural laws as manifested in climate, in the distribution of moisture, and even in the origin and spread of civilization, I have felt at liberty to draw my illustrations from every quarter of the world, and from almost every department of science. These illustrations will show that man, even, however much he may boast of his dominion over matter, is the creature of climate; and that, only under certain favorable conditions, does he attain to the full development of his physical and intellectual powers. Such con ditions, it is believed, obtain in the Upper Valley of the Mississippi. Chicago, February I, 1S69. CONTENTS.

Chapter I. The Mississippi

river. The magnitude of the Mississippi — Area — Subordinate basins — Internal navigation — Character of Lower Mississippi — Characteristic vegetation — Overflows — Bluffs — Levees — Outlets — Approaches — Phenomena of waters — Geology — Area of alluvium and delta — Earthquake-action. ..... Page i

Chapter II. Mountains And Plains

Character of the water-sheds — The Appalachain Range — The Rocky Mountains — The Sierra Nevada — The Cascade Range — The Coast Ranges — Ridges of the Great Basin — Character of the sources of the Mississippi — Of the Ohio Valley — The Llano Estacado — Rocky Mountain Valleys — Colorado Desert — Valley of the St. Lawrence — Pacific Railroad routes — Rdsume". - 26

Chapter III. The Origin Of Prairies

Distribution of forest, prairie, and desert — Prairies not due to peat-growth — Not due to the texture of the soil — Not due to the annual burnings — Zones of vegetation — The Great Basin — Climatic conditions — Mean annual precipitation — Source of moisture — Periodical rains of California — Conclusions. - - 71

Chapter IV. The Origin Of Prairies

— continued. South America — Primeval forests of Brazil — The Llanos of Caraccas— The Pampas of La Plata and the Gran Chaco — Patagonia — CONTENTS. Its deserts and mountains — Peru and the desert ofAtacama — Wind and rain charts — Europe — Plains of the Black Sea- Steppes of the Caucasus — Plateau of Central Asia — Desert of Arabia— Africa — Sahara — Guinea — Basin of the Mediterra nean—Australia — Resume — Explanation of Map. - - 112 112

Chapter V. Forest-culture And Irrigation

How plants grow — Effects of forests on health — On animal life — Effects of disrobing a country of forests — Rapid destruction of forests in the United States — Forests, their lessons — They modify climate — They retain moisture — Tree-planting — Irrigation — Practiced at an early day on both hemispheres — Successfully introduced on the Rocky Mountain slopes — Feasibility of its application in California, the Colorado Desert, and the Western Plains. ---------- 141

Chapter VI. Climate

Definition of climate — -Atmospheric currents — Rains and winds — Cloud-bursts — Isothermal lines — Gulf-stream — Evaporative , power of winds — -Isotherms of the United States — Climate of the Pacific Slope and Great Basin — Phenomena of the seasons — Table of temperatures — Of rain-precipitation. - - 172

Chapter VII. Cultivated Plants

Conditions of climate and soil restricting the range of plants — Of the soil in reference to the growth of particular plants — Maize, — Wheat, — Oats, — Rye, and Barley — Natives of the plains of Central Asia — Rice — Sugar-cane — Sorghum — Potato — Cotton — Tobacco — Grasses for pasturage — Exhaustion of the soil — Facilities for cultivation — Tables of population and production. 209

Chapter VIII. Geology

— IGNEOUS AND METAMORPHIC ROCKS. Geological structure of the Mississippi Valley — Tabular view of the different formations — Igneous rocks of different age Systems of elevation of mountain chains — The Lake Superior system The Primeval Continent— The Appalachian system — The Rocky- CONTENTS. XV Mountain system — The Pacific Coast Ranges —Igneous pro ducts — River systems — The Azoic system, associated with iron-ores — Iron-region of Lake Superior — Of Missouri — The Mytho logical age of metals— The present, the Iron age — Annual product of the world. 242

Chapter IX

geology — continued , — sedimentary rocks. Silurian system — First evidences of organic life — Area of Silurian- Lower Silurian— Potsdam sandstone — Pictured Rocks — Copper-region of Lake Superior — Lower Magnesian limestone — Lead-bearing veins of Missouri — St. Peter's sandstone — Cincinnati Blue limestone — Galena limestone — Upper Silurian system — Niagara limestone — Onondaga salt-group — Devonian system- Carboniferous system — Fluor spar, with veins of galena — Galena deposits — Silver ores of Mexico — Coal-Measures, their area — Thickness — Character of the coals — Permian system — Triassic and Jurassic series — Gold deposits of California — Copper deposits — Cretaceous deposits — Coal deposits. - - 272

Chapter X. Geology

— continued , — sedimentary rocks. Tertiary system — Marine of the Atlantic Slope — Fresh-water of the Missouri Basin — Marine of the Pacific Coast — Economic value of the Tertiary coals — Igneous products of the Great Basin — Comstock lode, its yield in silver — Drift-epoch — Drift-action in the Mississippi Valley — Erosive action on the Pacific Slope and in the Colorado Plateau — Terraces of Modified Drift — Loess — Sand-dunes — The Great Lakes — Drift-phenomena — Denudation — Area, depth, and elevation — Resume. - 318

Chapter XI. Influence Of Climate On Man

Geographical range of man, as compared with that of plants — Conditions of human life under different zones — Arctic life — Tropical life — Life in Northern temperate zone — Human energy displayed within certain isothermal lines — In Europe — In North America — Climate of the Southern States, and the condition of societv — Climate of the Northern States, and the condition of society — Effects of these differences seen in the Rebellion — Physical development. ...... CONTENTS.

Chapter XII. Origin Of Civilization

Valley of the Mississippi, its prospective population — Greece the cradle of civilization — Rome the inheritor of that civilization — Origin of Teutons and Celts — Characteristics of each race — Colonization of North America — National unity — Causes which promote it — English character — Their homogeneity as compared with that of the people of the United States — The civilizing effects of the Christian religion. ----- 377

Chapter XIII. Progress Of Development

Ordinance of 1787 for the government of the Northwestern Territory — Its effect upon the character of the colonization — First settlement of the region — Relative growth in population — Area of Western States — Agricultural products, their rapid increase — The assessed value of real and personal property — Indians — Their habits — Government policy towards them — The Mound-builders — Their civilization — Antiquity of their works — Conclusion. ----------- 401 ILLUSTRATIONS. Map — Showing the distribution of Forest, Prairie, and Desert, - 140 Map — Showing the Isothermal Lines of the United States, 200 Geological Sketch of the United States, - 272 Index, THE MISSISSIPPI VALLEY: ITS PHYSICAL GEOGRAPHY.

Chapter I. The Mississippi River

THE MAGNITUDE OF THE MISSISSIPPI AREA SUBORDINATE BASINS INTERNAL NAVIGATION CHARACTER OF LOWER MISSISSIPPI CHARACTERISTIC VEGETATION OVERFLOWS BLUFFS LEVEES OUTLETS APPROACHES PHENOMENA OF WATERS GEOLOGY AREA OF ALLUVIUM AND DELTA EARTHQUAKE ACTION. "The beginnings of a river are insignificant, and its infancy is frivo lous; it plays among the flowers of a meadow, it waters a garden, or turns a little mill. Gathering strength in its growth, it becomes wild and impetuous. Impatient of the restraints it meets with, in the hol lows among the mountains, it is restless and fretful ; quick in its turn ing, and unsteady in its course. Now it is a roaring cataract, tearing up and overturning whatever opposes its progress, and it shoots head long down from a rock; then it becomes a sullen and gloomy pool, buried in the bottom of a glen.

Recovering breath by repose, it again dashes along, till, tired of uproar and mischief, it quits all that it has swept along, and leaves an opening of the valley strewed with the rejected waste. Now, quitting its retirement, it comes abroad into the world, journeying with more prudence and discretion, through cultivated fields, yielding to circumstances, and winding round what it would trouble it to overwhelm and remove. It passes through populous cities, and all the busy haunts of men, tendering its services on every side, and becomes the support and ornament of the country. Increased by numerous alliances, and advanced in its course, it becomes grave and stately in its motions, loves peace and quiet, and, in majestic silence, rolls on its mighty waters, till it is laid to rest in the vast abyss." — Pliny, " Hist.

Nat." Lib. V. Magnitude of the Mississippi — The Missis sippi * River, when we consider its great length, the number and character of its tributaries — often exceeding the fii-st-class rivers of Europe, — the area of country which it drains, the vast system of internal navigation which it affords, and the populous towns which have been founded on its banks, may be regarded as one of the most striking topographical features of the earth. The rivers descending from the Atlantic and Pacific slopes are, for the most part, short and rapid, and are not navigable beyond the reach of tide-water; but this * The name is derived from the Algonquin, or Chippewyan, language — Missi, great, and Sepi river. To the same root, or corruptions of it, may be traced several conspicuous bodies of water in the North west.

The Indian name of Churchill River is Missi-nepi, probably identical in meaning with Mississippi. Gummi signifies water, or a collection of water, not running; thus, the aboriginal name of Lake Superior was Kitchi, great — allied to Michi or Missi — and Gummi, water; Michi-gan (Michigan) is a corruption of the same thing. In conversing with a Chippewyan Indian, he will describe any large body of running water, as Missi, or Michi, Sepi, or Sebi, and any large body of still water as Mitc/ii, or Missi, Gummi (great water) ; so that what he would regard as a generic term, we use as a specific term, which has become thoroughly incorporated with some of the most marked topographical features of the Northwest. INTERNAL NAVIGATION. 3 river-system penetrates to the heart of a continent, and, with its numerous tributaries, affords an inland navigation of unsurpassed magnificence.

Area — Subordinate Basins. — The Mississippi Valley comprises an area of 2,455,000 square miles, extending through 30 degrees of longitude and 23 decrees of latitude: — an area greater than that of all Europe, exclusive of Russia, Norway, and Sweden. It is composed of several subordinate basins, whose area, elevation, drainage, etc., are as follows : * Internal Navigation. — The Mississippi and its tributaries afford an internal navigation for steam- * Humphreys and Abbot, "Physics and Hydraulics of Miss. River." DISTANCE FROM MOUTH. HEIGHT ABOVE SEA. WIDTH AT MOUTH. DOWN- FALL OF RAIN. MEAN disch'ge PER SEC. AREA OF BASIN. River. Miles. Feet. Feet. Inches. Cub. Feet. Sg. Mile-:. Upper Mississippi. 1.33° 1,680 5,000 3S-2 105.000 169.000 Missouri 2.908 6,800? 3,000 20.9 120,000 5iS,ooo Ohio 1,265 1,649 3,000 4i-5 15S.000 214,000 Arkansas i.i'4 10,000 1,500 29-3 63,000 189,000 Red River 1,200 2.45° 800 39-° 57,000 97,000 Yazoo 500 210 S50 46-3 43,000 i3-S5o St. Francis 3S0 1,150 700 41. 1 31,000 10.500 Lower Mississippi. 1,286 416 2,470 30-4 675.000 1.244,000 boats, of more than 9,000 miles in extent.* They have proved the great highways by which, within a brief period, man has been able to penetrate to the interior of the continent, and to subdue it to his uses. * The Mississippi is navigable — From its mouth to St. Paul, . . . 1,944 miles.

And from St. Anthony to Sauk Rapids, . 80 " Making a total navigation of . . . 2,020 " Several of its upper tributaries are navigable — The Minnesota to Patterson's Rapids, . . 295 " The St. Croix to St. Croix, . . . . 60 " The Illinois to La Salle, .... 220 " The Missouri is navigable, at high water, from its mouth to Fort Benton, .... 2,644 " but ordinarily to 60 miles above the mouth of the Yellowstone (1,894 miles) . . . 1,954 " (The volume of water discharged by the Yellowstone is represented to be about the same as that of the Missouri ; and after the junction, the river attains a width of 2,000 feet.) The Ohio is navigable to Pittsburgh, . . 975 " The Monongahela to Geneva, . . . 91 " The Tennessee to Muscle Shoals, . . 600 " The Cumberland to Burkesville, . . . 370 " Some of its other tributaries, which have been slackwatered, give a navigation of 550 " The Arkansas is navigable, in flood, to Ft.

Gibson, 642 " but during its lowest stage, it is difficult for boats of the lightest draught to reach Fort Smith, . 522 " The Red river is navigable, in ordinary stage, to Shrevesport, ..... 330 " but only in flood, to Preston, . . . 320 " The St. Francis is navigable to Wittsburg, . So " The White River is navigable to Batesvillc, . . 175 " The Yazoo to Greenwood, . iaci " The Kaw has been ascended to Fort Riley, . . 100 " but the navigation is ordinarily precarious. The Platte is an important tributary of the Missouri, which, like the Canadian and the Arkansas, reaches to the base of the Rocky Moun tains, and spreads out over a wide space, so that it is totally unfit for navigation. CHARACTER OF THE LOWER MISSISSIPPI. 5 Character of the Loruer Mississippi. — " At the mouth of the Missouri, the Mississippi first assumes its characteristic appearance of a turbid and boiling torrent, immense in volume and force.

From that point, its waters pursue their devious way for more than 1300 miles, destroying banks and islands at one locality, reconstructing them at another, absorbing tributary after tributary, without visible increase in size, — until, at length, it is in turn absorbed in the great volume of the Gulf." * The shores of the Gulf, so far as relates to the Louisianian coast, are bordered, for fifty miles inland, by swamps, bayous, and lakes. The swamps generally consist of an oozy mass of mud, from twenty to forty feet in depth, resting on blue clay. Upon the hummocks, a variety of vegetable forms take root, unknown in the regions to the northward. Typical Forms of Vegetation. — Conspicuous among these is the cypress, which is first seen near the mouth of the Ohio, and is alwaj's found on land subject to overflow.

From a protuberance at the surface, a shaft rises straight to the height of sixty or eighty feet, without a limb, when it throws out numerous branches, umbrella-shaped, which sustain a foliage of short, fine, tufted leaves, of a green so deep as to appear almost brown. They grow so close together, that their branches inter- * Humphreys and Abbot. lock; and hence a cypress forest resembles a mass of verdure sustained in the air by tall perpendicular columns. From their branches, depend long fes toons of moss, which sway to and fro in the wind, like so many shrouds, — communicating to the scene the most dismal aspect. Arranged around the parent stem, are numerous cone-shaped protu berances, known as "cypress knees," which enable the roots of the tree to communicate with the air; a provision of nature which is essential to its vitality.

The cypress loves the gloomiest and most inac cessible portions of the southern forest, and where, for one-half of the year, the surface is submerged. Repulsive, then, as is its habitat, it is the most valuable of all the southern lumber trees. Soft, free from knots, rifting straight, and easily wrought, it is fit for shingles, boards, and finishing material. The palmetto, not the species of the Carolina coast, is another characteristic form of these swamps, and one which, by its peculiarities, at once arrests the eye of the northern traveler. It is perennial; and, from a large, tough root, throws up a stem six feet high, sustaining fan-shaped palm leaves, exactly ribbed, and of a rich green verdure. These are used for fans, for braiding into hats, and for thatching: the huts of the negroes.

These swamps, clothed with trees of abundant TYPICAL FORMS OF VEGETATION. and interlaced branches, springing from a muss of ooze tremulous to the foot, remind one of the estu aries and lakes, with their luxuriant vegetation, which stretched over large areas of the earth's sur face during the Carboniferous epoch — a vegetation which furnished no sustenance to the higher forms of animal life, and which flourished in an atmos phere probably fatal to air-breathing animals. These swamps are the chosen retreats of the alli gator, the lizard, and moccasin snake, and swarm with mosquitoes and other venemous insects. To man, they are impassable, except when flooded. To traverse them, he should be like Milton's fiend, qualified for all elements and all services; who, " With head, hands, 'wings, or feet, pursues his way ; And swims, or sinks, or wades, or creeps, or flies."

In connection with the southern vegetation, two other types may be mentioned; the live-oak and the magnolia. The live-oak is a noble tree — tall, with long spreading branches, and presenting almost as great a mass of foliage as the northern elm. Its range does not extend be}Tond latitude thirty-one north. The magnolia belongs to the tribe of laurels. The beauty of this tree has been greatly overrated. It is, according to Flint, only a fifth-rate tree, which grows in the rich alluvium of the Louisiana bottoms, where the soil is congenial to its full development. It is tall, graceful in form, with a smooth, light colored bark, like that of the beech. The wood is soft and useless. The leaves are glossy on the upper surface, like those of the orange, with a yellowish down upon the under surface.

The flower is large, and of a pure white, like those of the northern pond-lily, but twice the size. The odor is strong and not offensive. "Instead of dis playing," says Flint, "a cone of flowers, we have seldom seen a tree in flower which did not require some attention and closeness of inspection to dis cover where the flowers are situated among the leaves." * There are six or seven species among the laurels of the magnolia tribe. Overflow of the Mississippi. — When in flood, the river extends to a width of thirty miles, and the surplus waters find their way to the ocean through deep forests and almost interminable swamps. The ordinary channel is marked by an outline of woods. As the flood recedes, it leaves behind, in the bottom lands, a sediment as fine and as fertilizing as the Nile mud.

The course of the river is in a series of curves, from ten to twelve miles in diameter, sweeping round with great uniformity, until it " Mississippi Valley." BLUFFS. 9 returns to a point very near the one from which it was deflected. The current continually encroaches on the alluvial banks, until finally, during high flood, a crevasse occurs, when nearly the whole volume of water rushes through the newly-formed channel, known as a "cut-off." Hence, along its whole course are seen numerous crescent-shaped lakes which owe their origin to this cause. Sandoars accumulate at the mouths of the ancient channels, on which first rushes take root, and subsequently cotton-wood, thus forming lakes which, except in flood, become isolated from the river. The river being no where rock-bound in its lower course, and its banks consisting of the most comminuted materials, has great excavating power.* Bluffs. — The alluvial bottoms are ordinarily impassable, and the bluffs only afford sites for habi tations.

In a few instances, they approach the river, as at the Iron Banks, near Columbus, and the Chalk * The citation of a single case, which occurred at New Madrid, will suffice. Joseph Lewis (quoting, as authority, an old resident,) as mar shal, in 1798, was ordered, by the local Spanish government, to move the church one mile north, to prevent its being undermined. The distance was measired by a surveyor, and the order was executed. In 1811, the region having passed into the possession of another government, no pains were taken to protect the church against farther encroachments, when it fell into the river. My informant had seen the original plat of the town, which extended back from the river front four miles. There now remains a strip of the original plat, not more than sixty feet in width.

Banks, near Hickman, Kentucky; at Fulton, Ran dolph, Old River (but here the river has receded), and Memphis, Tennessee; at Walnut Hills or Vicksburg, Grand and Petit Gulf, Natchez, and Fort Adams, Mississippi; and at St. Francisville and Baton Rouge, Louisiana. All of the bluffs occur on the east side of the river, except the St. Francis Hills, and Point Chicot. The bluffs, as first suggested by Lyell, belong to the age of the Rhenish Loess, and ordinarily consist of beds of yellowish loam, sand, and clsy, with beds of lignite of an earlier age beneath. Levees. — To protect the plantations from over flow, a system of levees was commenced many years ago; and, to aid the extension, Coigress passed an act directing the proceeds of the sale of swamp-lands to be devoted to this purpose. Under the operation of this act, levees have been carried up the east bank, nearly as far as Memphis, and up the west bank to a point opposite the mouth of the Ohio.