Queenstown in an escarpment or long line of
inland cliff facing northwards, towards Lake Ontario. The Niagara, on
reaching the escarpment and issuing from the gorge, enters the flat
country, which is so nearly on a level with Lake Ontario, that there is
only a fall of about four feet in the seven additional miles which
intervene between Queenstown and the shores of that lake.

It has long been the popular belief that the Niagara once flowed in a
shallow valley across the whole platform, from the present site of the
Falls to the escarpment (called the Queenstown heights), where it is
supposed that the cataract was first situated, and that the river has
been slowly eating its way backwards through the rocks for the distance
of seven miles. This hypothesis naturally suggests itself to every
observer, who sees the narrowness of the gorge at its termination, and
throughout its whole course, as far up as the Falls, above which point
the river expands as before stated. The boundary cliffs of the ravine
are usually perpendicular, and in many places undermined on one side by
the impetuous stream. The uppermost rock of the table-land at the Falls
consists of hard limestone (a member of the Silurian series), about
ninety feet thick, beneath which lie soft shales of equal thickness,
continually undermined by the action of the spray, which rises from the
pool into which so large a body of water is projected, and is driven
violently by gusts of wind against the base of the precipice. In
consequence of this action, and that of frost, the shale disintegrates
and crumbles away, and portions of the incumbent rock overhang 40 feet,
and often when unsupported tumble down, so that the Falls do not remain
absolutely stationary at the same spot, even for half a century.
Accounts have come down to us, from the earliest period of observation,
of the frequent destruction of these rocks, and the sudden descent of
huge fragments in 1818 and 1828, are said to have shaken the adjacent
country like an earthquake. The earliest travellers, Hennepin and Kalm,
who in 1678 and 1751 visited the Falls, and published views of them,
attest the fact, that the rocks have been suffering from dilapidation
for more than a century and a half, and that some slight changes, even
in the scenery of the cataract have been brought about within that time.
The idea, therefore, of perpetual and progressive waste is constantly
present to the mind of every beholder; and as th