692
upon, and the only difficulty that
offered itself was in maintaining
the small gate in a recumbent
position; which its want of weight
prevented when immersed in water.
Captain Goodwyn's bolt appears
to remedy this inconvenience, but
it will require a good deal of
practice before the working of
the apparatus is satisfactorily
developed, especially that part
of it which is connected with the
large gate, the weight of which
is considerable. The details of
the apparatus for raising the
gates and keeping them in
position are fully represented
in plate XXV of the atlas.
It must be understood
that the mountain torrents
with which the works are con-
-nected, carry in their waters materi-
-al of all sorts, collected in their
passage through extensive re-
-gions of the forest. Trees of the
largest size root and branch
are frequently [swept away, struck through] thrown down, and
carried with an overwhelming
velocity along the course of the
river. Grass, branches, and hewn
timber left in the forests after the
carting season is passed, are
swept away, and gathered in
heaps on any obstruction that
offers itself to the opposing cur-
-rent, the effect of the onward
progress of this collected mass
is to carry away the object that
causes the obstruction with it;
and to any work like a dam
with suspended self regulating
gates
EN