Between the head of tide-water and Blue Ridge are comprised 29 counties of Virginia, and 15,386 square miles. Taking the two eastern sections together, we have a surface of 27,190 square miles, comprising 65 counties, or not quite 420 square miles to the average of the counties. This com bined extent is the region denominated Eastern Virginia, and the population of which by the cen sus of 1830, is represented by Tables II. and III. On this part of Virginia the white population is within a small fraction of 14 to the square mile; the slaves and free coloured united, very near 17 to the square mile; and the aggregate of all classes, within a small fraction of 30 to the square mile.
The third or Great Valley section, is in many respects the most remarkable of the physical por tions of Virginia. Lying between the Blue Ridge and the main Appalachian chains, and extending from the great bend of Potomac between Harper's Ferry and Hancock's town, about 300 miles to the northern border of Ashe county, North Carolina, and embracing 13,072 square miles, the mean breadth is 43 miles very nearly. This valley, as it is called, is a real mountain table land. By re ference to Tables 111. and IV., Article UNITED STATES, page 240 of this volume, the reader will perceive that there is a difference of from 300 to 1400 feet between the relative elevation along the oppo site sides of Blue Ridge. The tables referred to, expose also another remarkable phenomenon, that the Great Valley of Virginia rises from little more than 300 feet along the Potomac, to upwards of 2000 feet on the opposite extreme on North Ca rolina.
The surface of the Great Virginia Valley is in an especial manner broken and diversified, and in every part containing zones of highly productive soil. It is indeed the continuation of the Kittatinny valley of Pennsylvania and Maryland, and contains along the Blue Ridge a continuation of that im mense limestone formation which, in fact, in an opposite direction, extends over New Jersey, New York and Connecticut into Massachusetts. The declivity of that part of this lengthened valley which is contained in Virginia, presents some peculiar features. The northern and nearly one half declines to the north-eastward towards the Potomac, and is there drained by the Shenandoah, Cacapon and South Branch of Potomac. Southward from the sources of Potomac and Shenandoah, is a middle slope drained eastwardly through the Blue Ridge by James and Roanoke rivers. The extreme south
ern part falls to the north-westward, and gives descent to New River, or the higher part of Great Kenhawa. We thus discover that this table land is partly on the Atlantic slope and partly on the Ohio Valley; and that the inflected line that se parates the sources of James and Roanoke of the former, from those of Great Kenhawa of the latter river system, passes the mountain valley ob liquely.
Politically the Great Valley of Virginia is sub divided into 17 counties, and containing 13,072 square miles; each county contains within a small fraction of 770 square miles. The aggregate popu lation is 205,818, or a little above 15 to the square mile; but of these the whites comprise upwards of three-fourths.
Passing the table land, between Blue Ridge and Alleghany mountains, brings us on the Ohio sec tion of Virginia. The extreme length of thi&west ern slope is within a small fraction of 300 miles, from the northern boundary of Tennessee, to the extreme northern angle of Brooke county; the great est breadth 135 miles over the Kenhawa valley, but both extremes being narrow, the mean width is about 91 miles; area 28,337 square miles. The surface is in the far greater part mountainous or very hilly. The chains of the Appalachian system stretch over it very nearly parallel to the general course of Ohio river, in that part of that stream which bounds Virginia on the north-west side. The soil is as varied in quality as the surface is in feature, as every grade of fertility and of sterility may be found, the latter, however, greatly the prevailing charac ter. The elevation of the water at the junction of the Ohio and Great Kenhawa being 533 feet above the ocean level, and that point being only about 40 miles above the extreme lowest point of Western Virginia at the mouth of the Great Sandy river, we may regard all the land surface of the Ohio section as rising above 500 feet. The relative oceanic ele vation of Wheeling is 634 feet; therefore the Ohio river as a base to the great inclined plane, and as a recipient for the water of the western section of Vir ginia, forms in itself a deep valley, lying at a Mean of' upwards of 560 feet above the Atlantic Ocean, or on a level with Lake Erie, about mid-course along Virginia.