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Show EMIGRANT'S GUIDE . .tains and their compactness and elevation ; with the courses of ~iver~ · the width and depth of their particular valleys; and with the unifor~ity or asperity of the surface of the various ba~ins. . , It cannot be deemed presumption to assert, that th1s particular topographical knowledge has not been evinced by any Europ~an writer JJpon the United States. Most of them were n;en whose ~m~s we~e rendered unfit, by national prejudice, to enter m!o a phystcal •?vesbgation ; others came to abuse ; one or two to pratse ,; . and few mdeed have resided long enough in the country to form opm10ns of the people or climate from long observation,. or comparison. of well arranged fa,ets. The following sketch of the outline of the. Ohio ?asi~, wil~ enabl.e the reader to perceive the true cause~, why m reahty Its. chmate. IS hecessarily more severely col<l in wmter, and also, why m some mstances in summer, the condensed heat is greater than in most places on the coast of the Atlantic ocean. 'l~he extent and interiot· structure of the two basins of Ohio and Illinois have been descanted on ;* it remains to delineate their outline, and to show, from their exterior, the causes that produce the pe· culiar constitution of climate in this singular region. The Aleghany mountains ranging from N. E. to S. W. skirts along tha S. E. p~rt of the Ohio valley. Though not actually the boundary of the basin,t and not very elevated, this chain forms a very effective barrier against the warm winds of the Gulf Stream. Th~ AI~· ghany mountains are remarkable for their compactness, ruonmg m collateral riuges; there exists from the 42° to the 34° N. lat., no absolute interval. Where one ridge is cut by a river, the opposite one is a solid wall, and all are covered with a dense forest to the summit~ This character becom~s more distinctive, advancing southwest, and is most promiuent whpre the influence of such a mass of rocks and ·woods would prm.l'Clee the greatest effect; that is between 34° and 36° N. J:tt. At 34° N. lat. may be considered the nucleus of the whole mass of mountains. A~out 34° N. lat. the Al~ghany turns almost :Jbruptly to the west, and imperceptibly d~clining in elevation, finally disappeq.rs at \4° W. longitude from Washington city. Cumberland mouutain is the same chain that first appears near Angelica in the ~tale of New-York, and which traverses Pennsylva~1ia by the name of Cbcstnut ridge. In Virginia, this chain is known by various appel· Jations; to thf.'! soutb of tbe Great Kenhaw~, it assumes 'the name of Cumberlam.l, by which term it is known on the. southwest part of Virginia, and southeast of ]\entucky. On entering Tennessee between Cumberland and Clinch rivers, Cumberland mountain first ~urns S. W. by W., and about fifty miles within the state, as,sumcs a westerp range, very nearly along the 36° N. lat. Though, perhaps, f10t mor~ thaq 700 or 8~)0 feet elevated above the table land of the .Ohio valley, this minor c)lain does pot terminate until reaching west pf Tennessee river, upon the border of tbe 1.\'Iississippi alluvion. That part of tbe Al'eghany mountain which rises south of Tennes .. •e~ riyer~ cqntinq~s west-northwest from the nprthwest part of ' See pagf! 18'f. EMIGRANT'S GUIDE. 6eoruia tl1rough Alabama territory ~nd the state of Mississippi, until withirt thirty or forty miles ~f the Mississi_ppi river, i~ ter!ninates in high broken ridges. West of the latter r1~er, at 36 30 ~· lat., a ridue of hills reaches its bank near Cape Girardeau, by an 1mmense pre0cipice of limes.tone, .upwards of 400 feet hig~ ; .betwe.en which and the western extremtty of Cumberland mountam, IS an mterval of about 80 miles. Very nearly a similar distance intervenes betw~en the western termination of the Alegbany, and the eastern elongation of the Masserne mountains, south of Arkansaw ri'fer. Both the Maiserne mountains and the chain of hills which reachl*! Mississippi near Cape Girardeau, are continuous ridges emanating from the spurs of the Chippewan. A very striking feature distinguishes, not only the hil1s and mountains east of the Mississippi from those of the west, but a~)rds a stro~g contrast between the entire physiogn9my of the two regwns ; that Is, the dense aml unbroken forest tbat clothes the former, and the open nake<l prairies that compose the far greate~ part of the surface of the latter. This difference accounts satisfactonly for the rernarka .. ble change of climate between the border of the gulf of Mexico contiguous to Mobile bay, and that found west of the Mississippi river. Mr. Volney states, that soYth of 35° anJ north of 45° N. latitude, the climate of North America equalizes from the Atlantic ocean to the Chippewan mountains. How far this position is correct in the north section, we cannot j udge from personal knowledge; but upon tue south section actual experience enables us to pronounce it incorrect · and we have ·shown why such an uniformity canoot exist. A'review of the attendant map wiiJ exhibit the real width of the proper valley of the Mississippi below the mouth of Ohio ; anu the very confined range of the south winds from the gulf of Mexico into tile basin of Ohio. Mr. Volney has given a map of North Ameri.ca, upon which are_ rnarked the course·~t- of the winds from the trop1cs over the gulf of l\fexico and their final distribution over the continent. Such an artificial theory of American winds, rnu:::t excite some wonder in the mind of any person who has resided a number of years upon tbe nor!h border of the Mexican gulf, where the effects ought to be most 111 unison with the hypothesis, aud in harmony with each other. The late Mr. William Dunbar, who resided upwards of thirty years near Natchez, and who obilerved the phenomena of the atmospheric changes in the country with skill and attention, gives, in substance, the following as the routine of the seasons. Mr. Dunbar, after recounting the phenomena of the great sleet and snow storm, at Natchez, in the end of January and first of February, 1 800,t and other meteorological changes of that year, expressly state5, that on the 12th of December the thermometer was dowa at 12°. Th~ remarks of this gentleman, on the winds and weather of that country, deserve to be bdter known than they are ; we shall thereore transcribe them entire. ' ~ c-e pages 31, 83J 139. t See page 78 of this Treatise |