Слике страница
PDF
ePub
[blocks in formation]

ture, that all the laws of physics are recurred to for pur- longing to them, would be of great value. How much, poses of illustration ; even astronomy appears destined to then, does it concern the interests of the United States, contribute largely to the elucidation of the earth's structure, that rational estimates of the national resources, with all and, reflectively, upon that of the most distant planetary thuse infallible indications which should precede internal bodies. The cultivators of these three last branches are improvements, and whatever else aypertains io a monuprincipally engaged in collecting evidences of a former ment of such singular importance to them as a general state of things, from deposites containing organic remains, geological map would be, should be done with the utmost whence to deduce arguments for the true causes which accuracy? It seems called for both by the best interests have governed the present disposition of the stratified and the reputation of the country. masses of the crust of the earth. The eminent European Before I close this descriptive portion of my report, I writers in these branches are well acquainted with the in- shall ask to present a few remarks on the Arkansas and organic rocks, and, by their genius and untiring zeal, have Red rivers, which I trust will be found somewhat interest. made a deep impression upon the present age. The vo- ing: Both these streams are remarkable for their torluous luminous literature of which they are the parents, has found and serpentine course, and for the important deflections an immense number of adınirers amongst men of varied from their courses, which can be sometimes traced. The attainments, most of whom, though well acquainted with history of Red river illustrates well movements of this geological literature, have not had practical opportunities of latter class. From the point where it turns to the east, a examining nature extensively, and reconciling the compli- little north of 31° north latitude, it appears to have once cated and irregular manner in which, perhaps, the same flowed in a south direction down the line of the Alcbala. operation is effected in distant localities.

laya, in to the bay bearing that name, in the Gulf of Mex. The mineralogical branch is composed of men who, ico. There is a chain of lagoons on that line still rafted keeping up with the knowledge of the other branches, have up with timber, and no doubi, when a head was formed devoted themselves rather to a practical study of that por- capable of resisting the current, it gave the river iis present tion of the geological series which comprehends the metal- easterly direction into the Mississippi. In thuse remote liferous rocks, and the other productive branches. In periods when the False Washita and the other tributaries England, the demand for useful information from this class of Red River were working out its channel, the deposites is so great, that the profession of mineral surveyor has of timber must have been immense, not only filling its grown out of it, one entirely unknown at present in this channel to the Gulf of Mexico, as I have supposed, but country." In estimating the value of an estate there, the rafting up its present channel as low down as its present capacity of the agricultural surface is not alone considered, mouth in the Mississippi. The remains of those ancient but a great importance is given to the probable perpendicu- rafts are still to be seen near its mouth, adhering to its lar value of every acre, as it can be computed upon geo- | banks, the main body having rotted away, and passed down logical principles. The value of an estate to an individual with the current, to the point where the operations comdepending very much upon these circumstances, men of menced of clearing out the present raft. But even now, long experience and approved judgment are alone contided such is the abrasion produced by the river, that the annual in. If this, as it must be seen to be, is of so much conse accumulation of timber at the head of the great raft is quence to individuals, of what immense importance is it very great, and the consequent inundations from back water not to the State Governments, in putting their enactments very injurious. When the great work of cutting the raft into operation, to select individuals of the greatest experi- out is accomplished, an immense quantity of rich lands ence? For bow is that complex appearance of rocks in will be brought to their true value, and the salubrity of the different parts of the same country, which, though alto- country much improved. * gether different in their external cha ers, may be true These chains of lagoons are found both on the north and equivalents of each other, to be reconciled by men who south sides of Red river, and are amongst the immediate have only studied them in books? or how can men claim causes of the insalubrity of the climate during certain to have their opinions confided in respecting the tendency, months. The past summer was intensely hot and dry, direction, and quality of metalliserous veins, or the probable and one of these large lagoons, near Lost Prairie, on the existence of coal measures, upon which the outlay of great | Mexican side of Red river, a beautiful tract of land over capitals depends, who have never been down in a mine, which I passed, had experienced so much evaporation and have studied minerale only from cabinet specimens ? that it could not preserve its fish; the water became glairy, In geology no learning can supply the place of experience. and incapable of sustaining them, and they were faling A geologist may be an indifferent analyst, but certainly no dead on the surface. man shvuld be presumed a geologist merely because he is The course of the Arkansas is, in like manner, subject a learned chemist or a profound mathematician. Such an to constant change, as a small circumstance will lead to the important trust, therefore, as is comprehended in the geo. Jeflection of this noble, but 100 uncertain stream. The logical survey of a State, should be confided only to min lodgment of a tree will be the commencement of a bar that of long-approved experience.

will throw the current to the other side, which, beating I have thought these observations not out of place, be against a low and weak part of the opposite alluvial bank, cause, in the incipient encouragement now given to geoJogy by some of the State Governments, and which will *When Caplain Shreve, so much distinguished for his skill and dili; probably be done by all of them, it is important that the

gence in removing this rafi, came upon the ground in the spring our

1833, he found it dead water in Red 'river for forty mules below the few individuals in the country who have the requisite ex timbers which formed the raft, and which then exiended up the river perience, should not be overlooked in favor of others, who for at least one hundred and fifty miles. About one third of the sup: are perhaps not aware themselves of the extent of prac

face of the river was occupied with dead timbers, and pumerous liud

islands had been formed, on which trees and bushes were growing tical experience required to make any man's labors valuable, There were a great many bayous and low places, by which the water and worthy of being transferred to geological maps of the

of the river was led to various lagoons and swamps, once the ancien! countries they survey. It must be evident that a geological | and, confining the stream to its old channel, produced a current.com

bed of the river; these he stopped up with timber taken froin the rafl; map of any country, upon which all the important mineral three miles an hour. The general depth of the river was twenty five and metallic deposites should be accurately laid down, with

feet, but in other parts where nud banks existed, the depth was only

fifteen. As soon as the raft was sufficiently cut nul to restore a good their direction, extent, and other important incidents be. current, these were swept away, and an average depth of twenty five

feel produced. During the first scase be succeeded in removing * Mr. William Smith, who has received the first. Woolaston gold

abut geventy miles, and there is evity reason to believe that in the medu fri m the Geological Society of London, was a mincral survejur,

course of 1335 Captain Shreve will have opened a gimmel sleuntual and the author of the first geological map of England.

navigation the entire length of the rall.

[blocks in formation]

will, in a short time, if the bank happens to form a reach Sometimes, during the great freshets which descend from there, wear its way through, leaving an island and a chain the upper country, the river not only breaks through the of lagoons in its old bed. In the vicinity of the Mammelle reaches of land which jut out into the river, but absolutely mountain is an immense swamp, through part of which I gets under the extensive sand beaches, and, lifting them passed, and which contains, perhaps, thirty thousand acres. up above the general level of the country, deposites them The timber on each side, being much killed by the water, upon it. In this way, I have observed considerable porslands dead in innumerable lofty bare masts, forming ations of rich plantations, distant several hundred yards from picture of perfect desolation. The cypress," the cotton- the edge of the river, buried several feet deep beneath a wood poplar, t and the populus monilifera, the hackberry, # barren sand. At other times, the freshets plough the whole the triple-thorned acacia, $ and many other trees, attain an of the vegetation up from the ground for thirty or forty iinmense size here. The lagoons in this swamp extend acres, and deposite it in a mass, with all its tinler, upon for several miles where the oid bed of the river was; wild some beach lower down.* This is the general character geese, ducks, and other aquatic birds, are here in incredi- of the Arkansas as I have observed it for several hundred ble numbers, as well as swans occasionally. Nothing can miles, and I have been told by those who have visited it be more singular than the aspect of the trees in this wild nearer to its sources, that it has, in some places, abraded place. Their trunks appeared to be painted red for about the whole surface of the country for several miles in width. fifteen feet from the ground; at that height a perfectly level These abrasions are more interesting to the geologist red line extended through the whole forest, inarking the than to the planter, for the fresh fracture enables him to rise of the waters at the last great inundation, which oc trace for great distances the party-colored deposites, altercurred in June, 1833, when the Arkansas rose thirty feet. / nating with each other, some white, some red, some gray, Millions of acres of rich hottom land of these countries are and often intermixed. Some parts of the banks are from thus rendered useless, and can never be brought to their one hundred to one hundred and thirty feet high, and as. intrinsic value but by levées, constructed at particular sume an important appearance in a country where much points, to keep out the waters from the direct course of the of the surrounding land is at a low dead level. About fisty river, and the back waters of the bayous that empty into miles from Little Rock the Red Pine blalls occur, which the river. Until measures of this kind are taken, these the river is fast wearing down. Twenty miles lower down districts will be a nuisance to the settlers, both in respect are similar bluffs of a lighter color, called the White bluffs, of their insalubrity, and their being the resort of the nu and about thirty miles lower down are the Pine bluffe, merous gangs of wolves which infest the country. I spent which are higher than the others. At the Red Pine blufis one night in the swamp alluded to, that of the 22d No- there is a bed of limestone, seen at low water, formed of vember last. The thermometer had fallen to 24° Fahren- | broken down oyster shells, like those in the Saline river. heit, and strong ice was making. The noise made by the This is the only calcareous deposite within my knowledge incessant howling and yelling of these animals exceeded in the banks of the Arkansas east of Little Rock, except ang thing I had ever heard, some barking in one tone, one I afterwards saw in the high banks at the post of Arsome screaming in another, as if each was suffering bodily kansas. They all present a fine study of Huviatile deposites, pain. This uproar is generally loudest just before the ap- not only in the party-colored seams of the old banks, but proach of day, and appears intended as a signal for strag- where they are at present forming on the surface of the glers to come into the wilderness, where they usually crouch country. during the day.

This immense river has its sources six or seven hundred From this point of the river down to its mouth, a dis. miles apart. Its southernmost branch, the south fork of the tance of about three hundred miles, a fine opportunity pre- Canadian, receives streams which rise near the thirty-fourth sents itself of studying not only the structure of this vast degree of north latitude ; its most northerly source is from boily of rich alluvial land, but of the action of the river, the Rocky Mountains, between 39° and 40°; and its most and I passed a week in following it to its junction with the eastern sources, including the heads of the Verdigris, Ne. Mississippi, lanıling, and examining the country at many osho, and Illinois, rise about 38° north latitude, at least six interesting points. The whole line presents a succession hundred miles from the central and principal sources in the of reaches, sand bars, and mutations, produced in the man- Rocky Mountains. The southernmost sources flow through ner I have before mentioned, and the serpentine course thus an ancient deposite of red argillaceous matter for several established doubles the distance. Its general course to the hundred miles, and it is this which colors the Canadian and Mississippi is southeast, but it is constantly, every five or its branches. The western and northern sources bring six miles, describing curves, and following the direction of down mineral matter of different colors, but to the east the southwest and northeast. Tre channel is thus alternately sources take their rise in a bigh siliceous country, and their on the right and left bank of the river. Sometimes an ex mineral deposites are indicative of their origin. 'The tensive sandy beach will project itself from the opposite branches of the Arkansas, included in this area, are nushore, and just so far into channel as to render it very merous; the Illinois, the Neosho, the Verdigris, the Cadifficult to get over with a boat drawing three feet. These nadian and its two principal tributaries, are all fine rivers, beaches sometimes cover more than fifty acres of land, and and would belong to the class of most important Euroare thrown up by the stream as it abrades the banks at

pean streams. They are of unequal length, and, being the foot of wbich it runs. The banks being thus constantly separated by great geographical distances, are subject 10 undermined by the action of the river, immense masses of increase their volume at distinct periods; and this volume, timber, together with the lofty canes, twenty to twenty-five on account of their unequal length, being emptied at disfeet high, that grow up with it, fall into the river with the tinct times into the main channel of the Arkansas, the deearth abuut their roots, and thus at the same time form the posites which this last leaves, in its irregular progress to snags and sawyers which embarrass the stream, and a the Mississippi, are characteristic of the mineral sulistances point of resistance which gives a new direction to it. which its tribularies and their branches pass through. The

Canadian, which passes through a red carth, has always * Cupressa disticha. + Populus angulata.

dull red waters, like those of Red river, arising still furiher + Cellis integrifolia.

& Acacia triacanthos. 11 Some conception may be formed of the difficulties which first set.

south. We are, hence, enabled to assign the red deposites llers have lo contend with in these frontier settlements, hy slating that to the materials transported by that stream, whilst the a very respectable inhabitant, who resides about fif y miles west of Little Rock, absolutely rode on horseback, with his bride, to visit some friends, up the bed of the Arkansas river two hundred iniles, fording | dred and forty miles from Little Rock.

* There is a fine instance of this at Mons. Barraques, about one hun. the river from sand lar to sand bar.

[blocks in formation]

whiter and siliceous deposites may be attributed to the greatest quantity of solid matter towards the mouth of the northern and eastern tributaries, whose waters, including Mississippi, consigning it to the ocean, which meets the those of the Poteau, that comes in further east, are all more deposites and distributes it into levels, to be probably laid clear. Those who have had opportunities of observing the dry at some future day, as the allurial plains I have been eccentric movements of floods of this class, soon learn to speaking of have already been. The lowest state of the distinguish what circumstances, whether arising from par Arkansas op ors during the months of July to November, tial eddies, owing to the change of level produced in pe inclusive. During a portion of this time, it is often not riods of inundation, or from ordinary mechanical causes, navigable from the Mississippi to Liule Rock. At this have produced both the regularity and irregularity of de- stage of the water, the current is sluggish, the water quasiposites; and how it is that blotches of mineral matter, both stagnant, and the solid matter held in suspension very trilarge and small, are found enclosed in deposites of a ho- filing, although always sufficient to tinge the water. A set mogeneous character, differing from them, just as the of experiments might be conducted, showing the mean whiter matter of the eastern branches of the Arkansas,

quantity of sedimentary matter brought annually down du. brought down by the Illinois, is found enclosed in the ex ring the rises of the river, and during the low-water periods. tensive beds deposited from the waters of the Canadian. It | Furnished with the cubic quantity of solid matter thus obis in the study of phenomena of this character, where flu- tained, and applying it as a divisor to the whole quantity viatile deposites are effected upon so immense a scale, that of fluviatile deposite contained in the entire alluvial area, perhaps an explanation of many different prelensions of we might approximately assign a chronological period for mineral matter, observed in older indurated rocks, may be the origin of these rivers, the commencement of these depossuggested.

iles, and the withdrawal of the ocean from these countries. I observed many superficial deposites which had been 'The period of their fitness to receive the human race might made, perhaps within ten years, by the annual inunda- thus be found to accord wilh particular indications of the tions : layers of white clay, sometimes of white sand, with existence of the aboriginal race. occasional intermixtures of both superimposed upon each other, and at times large blotches of whitish clay, were en * I would respecifully suggest to the officers in garrison at the fron. closed in a regular deposite of red. One day I followed,

tier pasis on the rivers I have named, especially those ai For Ton son,

on Red river, Fort Gibson, near the Arkansas, Fort Leavenworth, on for a considerable distance, an old dry bed which the river the Missouri, Fort Snelling, Jefferson Barracks, and Baton Rouge, og had abandoned for a new passage at the foot of the right the Mississippi, to institute experiments with his view. It would be

important to have them conducted in various places, near the sources bank, isolating a high ridge between the old and new beds,

of ihe great rivers, iminediately below the mouths of their respectire where the young wood was beginning to grow very thick tributaries, and al points near to where the great rivers disemburgue. ly, on a surface from whence all the timber had evidently

We should thus in time possess statemenis of the accumulating solid

contenus held by these streams in their progress to the ocean, and te been swept when the new passage was made. . The inuni able to give thein a very extensive application. Since my return, and dation of June, 1833, had deposited about an inch of dull as this report was going to the press, I have seen, for the first time, an

interesting paper by Leonard Horner, Esq., a distinguished meinker red argillaceous matter over a great part of this dry bed, of the Geological Society of London,“ on ihe amount of solid maller which extended many miles into the country, and present suspended in the water of the Rhine," which, in the hope it may ened the appearance of a reddish sandy valley, about three courage gentlemen in the army to undertake the experiment I have

recommended, I shall append i this no!e. hundred yards broad, containing many accumulations of "The attention of geologists has been more particularly directed of sand and dead trees, the old sond bars and snags. Every late to the importance of ascertaining the quanti:y of solid maller held

in suspension in the water of different rivers, as affording a measure thing boro a very desolated aspect; it was a huge chasın to

of the amount of abraded stone transported to the sea, there to constiappearance, furrowed out through a fiat country by the tute ihe materials of new strata, now in priigress of formation. temporary passage of a great river, which had not left a “During a late residence at Bonn, I began a series of experiments

on the quantity of solid maller suspended in the water of the Rhine, drop of water behind it. I saw no symptoms of animal in that part of ils course. Several interruptions prevented me from existence, except the track of a solitary deer, and a few advancing beyond the first steps of my proposed inquiry; but having

no iinmediate prospect of being able to resume it, I venture to offer turkey buzzards wheeling about in the air, and scanning even this small contribution to science, as the facts I ascertained may the surface in their characteristic manner, in search of car not be considered without value. rion. Upon the edges of some of these ancient banks of

"I made iwo sets of observations, the one in the month of August,

and the other in November. The apparatus I used was very simple, the river are several Indian mounds, with trees sometimes but answered the p'rpose perfecily; as it may be constructed in a growing on them, some of them about five hundred years

very short time, and almost in any situation, the facility of making

the observations ought to increase the chance of others of the same old: great quantities of Indian arrow heads are strewed

sort being made elsewhere. It consisted of a stone boule, capable of around, made of the siliceous mineral of the Washita hills, containing about a gallon, and furnished with a cork covered with and soine have been found buried several feet beneath the

leather, and greased; a weight of about ten pounds was aliached to

the bittom of the bolile by a mope of such a length that, when the surface; facts which show that this alluvial country, wbich weight wuched the ground, the mouth of the bottle mighi be at the de was possessed by a few bands of the Quapaws when the

sired distance from the bottom of the river. A rope was allached to

the ear or handle of the bottle, by which it was let down, and a string whiles first began to occupy it, has been inhabited by the was fastened to the cork. As soon as the boitle had reached its des aborigines at a very distant period.

tined position, the cork was withdrawn by means of the string, ih It will perhaps not be found impossible hereafter to as

boulle became filled with the water at that particular depth, and was

then inslanıly drawn up: The water, as soon as drawn up, was empsign approximately some limit to that period, when the set lied into gliss jars, on which I had previously parked a certain meas. tlement of the country shall bring other data forward, which

ure. The quantity of water on which I intended to operate was a cu•

bic frot, or 1,000 ounces, and I collected it at diferent times; for inconnect themselves with the geology of the country. It is

stance, after one-third of a cubic foot had stood in the jars for some true, the deposites made by the annual inundations are days, I drew off the clear water with a syphon, and another third of naturally too irregular and variable to afford systematic

water, fresh taken from the river, was added to the sediment left at

the bottom of the jars from the first; that was allowed to stand, the data for the computation of a period for the origin of these clear water was again drawn off, and the last third was added in the fluviatile beds; but whenever a careful inquiry of this kind

same way. When this had stod a sufficient length of:ime, the acco

mulated 'sedinent was reinoved to an evaporating dish, (a common is made, it will be found important to note them very ac

saucer will do quite as well,) and carefully dried in a gentle heat. curately. It would not be a difficult undertaking to calcu The cried mass was the amount of solid matter held in suspension in

a cubic foot of water, and now in the state of indurated mud. late the approximative amount of sedimentary matter

"First set of observations. The water was taken at the distance brought down annually by the Arkansas, or any of the of one hundred and sixty-five feet from the left bank, and a depth turbid tributaries of the Mississippi. The main rise of the

of six feet from the bottom of the river, the total depth of the river al Arkansas and Missouri, caused by the melting of the snows

that place being thirteen feel. It was in the month of August, and the

Rhine was unusually low. The water in the river had a yellowish tinge, of the Rocky Mountains, usually takes place in June ; and and was turbid; taken up in a glass, it was like the New river water, these rivers are irregularly swollen during the winter and

in London, after rain. The residuum, when dried in the manner

above mentioned, weighed 21.10 grains. It was of a pale yellow spring months by rain : al these times they bear along the ish brown color, smooth to the feel, not grilly; and it effervesced

[blocks in formation]

ex

Amongst the most interesting results of my late tour, 1 navigation, where fifty millions and a much greater nummust enumerate, first :

ber migbi he asserted—of North Americans have yet to The establishinent of the fact, from personal observation, establish themselves, where the amount produced of sugar of there being, in the State of Missouri and the Territory and cotton, which excites the admiration of our own day, of Arkansas, an amount of the ores of lead and iron, of an will be referred to as the germ of production hereafter ; excellent quality, not only more than adequate to any esti · where, when populous cities, increased shipping, and well mate of the domestic consumption of this nation, but such protected plantations, shall have placed these imperfectly as may justify the expectation that it will form an impor- known regions in the same class with the most powerful tant element hereafter of commercial exportation from that portions of the earth; who can doubt but that a part of part of the world. When it is considered that the sulphuretibe immense wealth thus accumulated will be invested in of lead forms, as described in this report, such an impor. working the inexhaustible mines which lay, as it were, at tant portion of the solid roik at one point, and that the very door of New Orleans, a ciiy evidently destined to ists, in an equally profuse manner, perhaps, through van rank hereafter amongst the first in the world ? If one narious points for a distance of five or six hundred miles, * tion can ever permanently undersell the others in those this language will not be deemed extravagant.

metals, it must be one possessing mines from whence they · But looking forward to the future prospects of these re can be extracted with equal facility as from those in ques. gions in the miring branches of industry, who, that has tion, and exported with so little charge. had but a glimpse of those fertile alluvial territories to the I consider it also as a result of great importance, that south, penetrated by go many thousands of miles of river the extensive investigations which I have su recently made,

have gone, without exception, to strengthen the opinion I briskly, but was not wholly dissolved, when diluled muriatic acid submitted to the Geological Society of London, in 1828, was prured upon it. In appearance and properties it was undistinguishable from the loese [a yellowish gray Inam) of the Rhine valley.

as to the series of rocks in the United States being the na** A cubic foot of distilled water weighs 137,5 grains; therefore, the tural equivalent of that observed in Europe, froin whence olid matter amounted wihe one twenty Livúsand seven hundrel and we may infer that the causes which operated to bring thiriy.fourth part of the cubic foot of water. . Second set of observations. -The water was taken up in the mid

the rocks there into the particular order of superposition they dle of the river; and frin about a foot below the surface. It was the preserve, have operated here, and probably have acted upon month of November, and a great deal of rain had fallen some time before and during the observations. The Rhine was of a deep yellow,

ihe whole crust of the earth. It is truo we have not yet and more turbiil than in August; but when taken up in a glass, it was found that remarkable portion called the oolitic formation, not very different in appearance from what it had been then. The lying above the coal measures, but this is only a part of cubic foot of water, in place of bring collected on three different oc. casions, was taken up on seven ditforent days, with intervitls of three

the series ; and in every country where geology bus hithdays between each * The residuum, when dried in the same manner, weiched thirty, ries is wanting. At many points of our Ailantic coast,

erto been practically studied, some part or other of the sefive grains, which is the one twelve thousand five hundredth part of matter in one cubic fort of the water.

including the city of Washington, there is no rock inter" It was my intention to have repeated these observations at differ. vening between the superficial detritus and the gneiss, ent seasons of the year, to have made a profile of the bed of the river froin shore to shore al Bon, and to have ascerlained the velocity at

which is the lowest rock but one of the whole series. Lodifferent parts of the stream, so as to get a mean velocity; the depth calities, with imperfect arrangements of this nature, are of the river I had an opportunity of seeing, for there is a gauge at ihe port i lutl was obliged to leavé Bonn suddenly, and could not accom

like a harp, where, though some of the party-colored plish iny desiaus.

chords may be wanting, yet the rest aro there, and pre" The aluve experiments show that the quantity of solid mat!er sus serve their unchangeable superposition to each other. pended in water, which, in the mass, has a turuvid appearance, may lię very trifiing. But the extent of the waste of the land, and of ihe solid

This correspondence of structure will result in making the materials curried to the sia, which even such minute quantities indli principles of the science of geology, like those of geomecale, is iar greater than we migh! he led to marine possible from such fractice. It is only when we take into account the great volume of

try, applicable everywhere. water constantly rolling along, an: the prodigious multiplying power It is a remarkable circumstance, as I had occasion to anof time. that we are able to discover the inagnitude of the operations of nounce in 1828, that, with the exception of the tertiary this silent but unceasing agency. In the alisence of more accurate data for my calculations, for the sake of showing how large an extent

and subcretaceous beds of the coast, nothing more recent of waste is indicated hy water holding no more solid matter in suspen than the coal-bearing series had been found in the United sion than is sutñcient to disturb iis transparency, I shall assume ihat the Rhine at Bond has a mean annual breadth of twelve hundred seet,

States. A fact so unusual in a continent of such great exa niean depth throughout the year of tifteen feel, and that the mean lent as North America, can hardly be attributed to denurelocity of all paris of the stream is two miles and a half per hour. These assumptions are probably not hurdlistant from the truth. I shall

ding causes, and would rather lead us to the inference that take ilic average amount of solid maller in suspension to be twenty.

this part of the globe has in fact emerged from the ocean eight grains in every cubic fol of the water

before the continent of Europe did, and that, geologically "If we suppose a mass of water of a funt in thickness, 15 feet in depth, and 1,200 feet in length, we shall have a column across the riv.

speaking, in relerence to the history of the earth, this has er containing 14,000 cuivic feet; and 18,000 multiplied by 28 gives very strong clains to be called the old world. If no de391,000 ruins of solid matter in that column. "A cubic foot of distilled water weighs 437,500 grains; and, if we

nudding causes adequate to the phenomenon have been in take the solid matter as having a specific gravily of 2.30, a cubic foot

action, we must cither adopt that opinion, or suppose that, of it would weigh 1,093,730) grains.

whilst other parts of the subaqueous world were receiving "Tihe river run with a mean velocity of iwo miles and a half in the hour, 1 },200 such columns would pass a line stretched across the river

sedimentary deposites, the waters of the occan, which corerery hour, and 316,00 such columns every twenty four hours: (1,760 ered the vast area, devoid of the entire oolitic system, were yards in a mile equal to 5,250 feet multiplied by 24 equal to 13,200, and situated so as not to receive any sedimentary materials. 13,20 ) multiplied by 24 equal to 316,800.)

11316,876 coluinns be multiplied by 501,000 grains, and the pro The opinions I communicated in 1828 have been confirmduct, 133,567,200,000, be divided by 1.033,730, (the number of grains in ed by my late tour, and strengthen the conclusion to a cubic foot of the solid matter, we have 1-15,980 cubic feet of stone carried down by the Rhine past the imaginary line every twenty-four

which my judgment has been for some tinie coming, that hours-a mass greater in bulk than a sulil tower of masonry sixty feel this continent is much older than the European continent. square, and fry feet in height. If we multiply 145,980 by 365, we bave 1,973,433 cubic yards carried down in the year; and if this pro:

It has not, however, been found easy to suggest for the cess has been going on at the same rate for the last two thousand duration of geological events, periods of which our own years-and there is no evidence that the river has undergone any ma. chronological methods shall be the measure. In the other terial chance during that period then the Fhine, must, in than tiores hemisphere it has been found that species have not changed yard thick, extending over an area more than thirty-six miles square. materially during the present order of things, which, as How much further back we may legitimately carry our calculations, I leave it to those to fix who consider that there are any data to enable

far as we can judge, comprehends the existence of man, us even to gues9 at what epoch the Rhine was different from what it and does not include that portion of time when any of the now is, either in respect of the vulume or the velocity of the stream, in tertiary beds became dry land. There is scarcely any that part of its course at least to which the present piper refers." North to the Ouisconsin country.

reason to suppose that the remains of man have been found VOL. XIV.--A 44

[blocks in formation]

in transatlantic countries out of the present order of things, executed in a much more creditable manner-presents the and none whatever in this hemisphere. For the produc- geological formations which occur from the New Jersey tion of our deltas, it must be evident that the full measure coast, on the Atlantic ocean, to Red river, on the Mexican of our chronologies would be wanting. If, therefore, du- confines, along an inflected line of about one thousand six ring so long a period as they comprehend, no material hundred miles, which I bave personally examined. Tho changos have been produced in species, we cannot but course to Nashville is south of west; thence, to Louisville, inser immense durations of time necessary to effect so east of north; thence, to St. Louis, nearly west; and the great a progression in organic existence, as is observed remainder of the section is on a course west of south. in the difference between recent and extinct shells, ani. The inclined lines were intended to represent the transition mals, and plants of the tertiary formations. What then beds, and the horizontal ones, which come in at the Cum. must be the relative antiquity of this continent, if so berland mountain, to represent the horizontality of the car. great a portion of it became dry land before the de- boniferous limestone. The short lines, about one-fourth position of the politic system in Europe, itself compre- of an inch, represent the localities where bituminous coal hending phenomena that seem to set at defiance every hope was seen. It would not have been practicable to introduce to compute & rational duration of time for their separate a regular scale of elevations, even had I possessed the maproduction ?

terials for one. I mention here, however, a few localities It will be felt, also, as an interesting step in the progress by way of approximation. The Alleghany ridge, through of geological knowledge, that we shall be enabled hereafter which the Potomac cuts west of Cumberland, rises between to trace with accuracy the littoral line so clearly made out Frankstown and Johnstown, Pennsylvania, to the beight by the subcretaceous fossils of the same genera which have of two thousand two hundred feet above tido water level. now been continuously found for near two thousand geo- The same ridge, west of Cumberland, in Maryland, is two graphical miles. It is evident that the ocean retired cotem- thousand seven hundred and fifty-four feet in height. Boporaneously from this line, either from the deepening of its tween Covington and the Great Falls of the Kanawba river bed, produced by distant causes, or from the elevation of the ridge measures one thousand nine hundred and ton the land; and this is the geological period which may be feet. These are, however, depressed points selected by fired for the commencement of those great deltas of rich engineers for canal communications. Many of the sumalluvial matter brought down by the rivers alluded to in mits exceed three thousand feet, and the general elevation this report, and which are hereafter to form so important a of the ridges in the Arkansas Territory over which I passed portion of the civilized earth.

appeared to me somowhat, though not much, inferior in It remains for me only to state that I have made ample height to those of the Alloghany ridges. collections of minerals and geological specimens of the Very respectfully, countries I have visited, all of which, when they reach this

G. W. FEATHERSTONHAUGH, city, will be placed at the disposition of the Government,

U. S. Geologist. The section which accompanies this report—and which [The map accompanying the report is necessarily omitthe state of the arts in this country well admitted of being ted. }

[ocr errors]
« ПретходнаНастави »