2. And be it further enacted, That it shall be lawful for a majority of the acting justices of the peace for the said county of Fairfax, together with the justices of the county of Loudoun included within the part thus added to the said county of Fairfax, and they are hereby required at a court to be held in the month of April or May next, to fix on a place for holding courts therein at or as near the center thereof (having regard to that part of the county of Loudoun hereby added to the said county of Fairfax) as the situation and convenience will admit of; and thenceforth proceed to erect the necessary public buildings at such place, and until such buildings be completed, to appoint any place for holding courts as they shall think proper.
3. This act shall commence and be in force from and after the passing thereof.
As at present bounded, the old channel at the mouth of Sugar Land run, at Lowe's Island,[3] is "the commencement of the line that separates Loudoun from Fairfax County and runs directly across the country to a point on the Bull Run branch of Occoquan River, about three eighths of a mile above Sudley Springs, in Prince William County." The Bull Run then forms the boundary between Loudoun and Prince William to its highest spring head in the Bull Run mountain, just below the Cool Spring Gap. The line then extends to the summit of the mountain, where the counties of Fauquier and Prince William corner. From the summit of this mountain, a direct line to a point[4] on the Blue Ridge, at Ashby's Gap, marks the boundary between Loudoun and Fauquier counties. A devious line, which follows in part the crests of the Blue Ridge until reaching the Potomac below Harpers Ferry, separates Loudoun from Clarke County, Virginia, and Jefferson County, West Virginia, on her western border. The Potomac then becomes the dividing line between Loudoun County, and Frederick and Montgomery counties, Maryland; "and that State, claiming the whole of the river, exercises jurisdiction over the islands as well as the river."
[3] "What is called Lowe's Island, at the mouth of Sugarland Run, was formerly an island, and made so by that run separating and part of it passing into the river by the present channel, while a part of it entered the river by what is now called the old channel. This old channel is now partially filled up, and only receives the waters of Sugarland Run in times of freshets. Occasionally when there is high water in the river the waters pass up the present channel of the run to the old channel, and then follow that to the river again. This old channel enters the river immediately west of the primordial range of rocks, that impinge so closely upon the river from here to Georgetown, forming as they do that series of falls known as Seneca Falls, the Great, and the Little Falls, making altogether a fall of 188 feet in less than 20 miles."—Memoir of Loudoun.
[4] Designated in an old record as a "double-bodied poplar tree standing in or near the middle of the thoroughfare of Ashby's Gap on the top of the Blue Ridge." It succumbed to the ravages of time and fire while this work was in course of preparation.
This completes an outline of 109 miles, viz: 19 miles in company with Fairfax, 10 with Prince William, 17 with Fauquier, 26 with Clarke and Jefferson, and 37 miles along the Potomac.
Loudoun County is preeminently a diversified region; its surface bearing many marked peculiarities, many grand distinctive features. The broken ranges of hills and mountains, abounding in Piedmont Virginia, here present themselves in softly rounded outline, gradually sinking down into the plains, giving great diversity and picturesqueness to the landscape. They are remarkable for their parallelism, regularity, rectilineal direction and evenness of outline, and constitute what is by far the most conspicuous feature in the topography of Loudoun. Neither snow-capped nor barren, they are clothed with vegetation from base to summit and afford fine range and pasturage for sheep and cattle.
The main valleys are longitudinal and those running transversely few and comparatively unimportant.
The far-famed Loudoun valley, reposing peacefully between the Blue Ridge and Catoctin mountains, presents all the many varied topographic aspects peculiar to a territory abounding in foothills.