[Footnote 12: Ibid.]

There is a huge belt of red land, known as "the red sandstone
formation," extending from the Potomac through a part of each of the
counties of _Loudoun_, Fairfax, Prince William, Fauquier, Culpeper,
and Orange, which, with judicious cultivation, might be rendered
liberally productive. Professor W. B. Rogers, in his report to the
legislature of Virginia, in 1840, described it under the head of the
"secondary formation in the northern district." "The general form of
this area," he wrote, "is that of a prolonged triangle, extending in a
direction from SSW. to NNE., having its apex at the southern
extremity, and gradually expanding until it reaches the Potomac.
Measured at a point on the Potomac between the mouths of Goose Creek
and Broad Run, its length is about 80 miles. Its greatest breadth, as
measured near the Potomac, and parallel to the road leading from
Leesburg to Dranesville, is about 15 miles. This, in round numbers,
gives 600 square miles for the area of this region."

Bottom lands of inexhaustible fertility and rich upland loams are
commonly met with north and south of Leesburg for a considerable
distance on either side of the turnpike leading from Point of Rocks,
Md., at one extremity of the County to Middleburg at the other.

Limestone occurs in vast quantities throughout this zone, and there
are present all the propitious elements that will be enumerated in the
treatment of the soils of other areas.

The land here is in a high state of cultivation and, according to its
peculiarly varying and unalterable adaptability, produces enormous