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264 P E R T E D U R H O N E .
After proceeding westward about a mile,
on looking back, the west side of the same
mountain is in front of the spectator, (w,
fig. 1,) the strata near the top of it are
seen rising behind each other, and here,
the under sides of the strata which are
visible, may be easily mistaken for the edges
of strata dipping towards the river. Let
the reader suppose a number of semicircular
disks of wood, each decreasing
in size, to be placed before each other ;
when seen edgeways they might respresent
the section, fig 2 ; but when seen in front,
the projecting rims of the larger disks
would represent the upper strata of the
mountain, fig. I, and would lead a hasty
observer to suppose that the strata were
curved and dipped northward. I have
seen numerous instances of a similar kind
in the calcareous mountains of Savoy.
A few miles beyond L ’Ecluse, before
arriving at Bellegarde, we descended to
view the place called la Perte du Phone,
where this river sinks into the eartii and
disappears. It may well be supposed that
a river like the Rhone, bearing the waters
from a hundred miles of the highest Alps
in Europe, before it enters the Lake of
P E R T E D U R H O N E . 265
Geneva ; and which receives beside all the
waters from the basin of the lake, seventy
miles in length, and all the rivers from
Mont Blanc and the north of Savoy, could
not suddenly sink down without producing
effects inconceivably sublime and awful ;
but they who expect this will be greatly
disappointed. The Bhone, before arriving
at la Perte, runs in a narrow bed, cut in
soft argillaceous strata, which repose on a
hard calcareous stratum ; but on reaching
this stratum, the waters have excavated a
deep tunnel in it, into which they fall with
considerable force, the rocks on each side
approaching so near that a man might
have strode across and seen the Bhone pass
between his feet at a great depth below ;
but the Sardinian government have widened
the space, by blowing up the rocks, in
order to prevent goods from being carried
over into Savoy or exported into France
without paying the duties. The deep tunnel
in which the Rhone runs, is, half way
down, divided into an upper and lower
channel, by projecting ledges of rock. In
winter, and early in spring, the river runs
below these ledges, and is nearly concealed;
and in one part masses of rock have fallen
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