tract is probably elevated 1,600 or 1,700 feet above the tide waters
of the Atlantic Ocean.

[1] It may be as well here to quote the formation of Cataracts
and Cascades, from Maltebrun's valuable _System of Universal
Geography._ "It is only the sloping of the land which can at first
cause water to flow; but an impulse having been once communicated
to the mass, the pressure alone of the water will keep it in
motion, even if there were no declivity at all. Many great rivers,
in fact, flow with an almost interruptible declivity. Rivers which
descend from primitive mountains into secondary lands, often form
_cascades and cataracts_. Such are the cataracts of the Nile,
of the Ganges, and some other great rivers, which, according to
Desmarest, evidently mark the limits of the ancient land.
Cataracts are also formed by lakes: of this description are the
celebrated Falls of the Niagara; but the most picturesque falls
are those of rapid rivers, bordered by trees and precipitous
rocks. Sometimes we see a body of water, which, before it arrives
at the bottom, is broken and dissipated into showers, like the
Staubbach, (see _Mirror,_ vol. xiv. p. 385.); sometimes it forms
a watery arch, projected from a rampart of rock, under which the
traveller may pass dryshod, as the "falling spring" of Virginia;
in one place, in a granite district, we see the Trolhetta, and the
Rhine not far from its source, urge on their foaming billows
among the pointed rocks; in another, amidst lands of a calcareous
formation, we see the Czettina and the Kerka, rolling down
from terrace to terrace, and presenting sometimes a sheet, and
sometimes a wall, of water. Some magnificent cascades have been
formed, at least in part, by the hands of man: the cascades of
Velino, near Terni, have been attributed to Pope Clement VIII.;