has a deafening effect upon the ear.

"The hill through which this singular perforation leads, descends in a
direction from east to west, across the line of the creek, and affords a
very convenient passage for a road which traverses it at this place,
having a descent in the direction just mentioned of about four degrees.

"The rocks found in this part of the country are principally sandstone
and limestone, in stratifications nearly horizontal, with occasional
beds of clay slate. A mixture of the two former frequently occurs among
the alternations presented by these rocks. A variety of rock resembling
the French burr occurs in abundance on Butcher's-fork of Powell's river,
about twenty miles northwardly of the Natural Tunnel. Fossils are more
or less abundant, in these and other rocks. Fossil bones, of an
interesting character, have been found in several places. Saltpetre
caves are numerous. Coves, sinks, and subterranean caverns, are
strikingly characteristic, not only of the country circumjacent to the
Natural Tunnel, but of the region generally situated between the
Cumberland mountain, and the Blue ridge or Apalachian mountain.
Bituminous coal, with its usual accompaniments, abounds in the northerly
parts of this region; and in the intermediate and southerly portions,
iron, variously combined, often magnetic, together with talcose rocks,
&c. &c. are to be met with in great abundance.

"The mountains in this vicinity--long. 82° to 84° W. from Greenwich,
lat. 35° to 36° N.--are among the most lofty of the Allegheny range.
Several knobs[3] in this part of the range, among which may be
enumerated the Roan, the Unaka, the Bald, the Black, and Powell's
mountains, rise to the height of at least four thousand five hundred
feet above tide."