diminution, there must be likewise a
correspondent diminution of the degrading
cause. -
The beds of torrents likewise in
cases when they are seated in the
hard rock, become defended from the
action of the atmosphere & from very
rapid changes of temperature, & from
the agency of ice; by the waters which
they contain - & in this case their decay
becomes almost imperceptible. -
- One of the most rapid torrents in
Britain is that of the Monach
in Cardiganshire . It rises under
Plinlimmon - & by a continued series
of falls is poured into the Rhediol
near Hafod under a bridge called
the devils bridge . - At the bottom
of the fall is a considerable bason
into which the torrent pours from
a height of at least 70 feet. - I
visited this spot in 1802 & accurately
ascertained the depth of the bason. -
5 years after I repeated the trial
but I found no perceptible difference. -