less so supernaturally
divided, have fatally intercepted the flow of the waters from far-off
countries. When did the great spirit of the river first knock at those
adamantine gates? When did the porter open to it, and cast his keys away
for ever, lapped in whirling sand? I am not satisfied--no one should be
satisfied--with that vague answer,--the river cut its way. Not so. The
river _found_ its way. I do not see that rivers, in their own strength,
can do much in cutting their way; they are nearly as apt to choke their
channels up, as to carve them out. Only give a river some little sudden
power in a valley, and see how it will use it. Cut itself a bed? Not so,
by any means, but fill up its bed, and look for another, in a wild,
dissatisfied, inconsistent manner. Any way, rather than the old one,
will better please it; and even if it is banked up and forced to keep to
the old one, it will not deepen, but do all it can to raise it, and leap
out of it. And although, wherever water has a steep fail, it will
swiftly cut itself a bed deep into the rock or ground, it will not, when
the rock is hard, cut a wider channel than it actually needs; so that
if the existing river beds, through ranges of mountain, had in reality
been cut by the streams, they would be found, wherever the rocks are
hard, only in the form of narrow and profound ravines,--like the
well-known channel of the Niagara, below the fall; not in that of
extended valleys. And the actual work of true mountain rivers, though
often much greater in proportion to their body of water than that of the
Niagara, is quite insignificant when compared with the area and depth of
the valleys through which they flow; so that, although in many cases it
appears that those larger valleys have been excavated at earlier periods
by more powerful streams, or by the existing stream in a more powerful
condition, still the great fact remains always equally plain, and
equally admirable, that, whatever the nature and duration of the
agencies employed, the earth was so shaped at first as to direct the
currents of its rivers in the manner most healthy and convenient for
man. The valley of the Rhone may, though it is not likely, have been in
great part excavated in early time by torrents a thousand times larger
than the Rhone; but it could not have been excavated at all, unless the
mountains had been thrown at first into two chains, between which the
torrents were set to work in a given direction.