' I
calcareous mountains in this part of Savoy,
some of which I intend afterwards to notice.
The valley of the Arve continued wide
till we approached the town of Cluse, when
the rocks advance on each side, leaving but
a narrow passage for the river and the road.
The rock at Cluse is a dark limestone,
bearing a resemblance to lias, which it may
probably b e : the workmen informed me it
contained shells, but I could not procure
any. These shells are ammonites, turri-
lites, and what have been called orthocera-
tites, though they are most probably en-
crinal remains, as they are described as
articulated, and ramified in arborizations.
Beyond Cluse there is a brown limestone,
and a dark-veined limestone. The valley
beyond Cluse is narrow and winding, and
presents some features of striking beauty.
The cavern of Balme and the cascade of
Maghlans are the objects that most attract
the attention of travellers. The cavern
would scarcely repay any one for the labour
of the ascent, who has seen the caverns in
Derbyshire, and the West Biding of Yorkshire.
The cascade is more remarkable for
its height than for its beauty; it falls over
a broad face of naked rock, 858 feet above
the road. This rock has been particularly
described by Saussure, as a remarkable instance
of horizontal strata, bent upwards,
and then curving backwards, and resting
against other strata, nearly horizontal.
After examining with attention for an hour
the course of the strata from the road, I
left the place, much inclined to believe,
that what M. Saussure regards as stratification,
is merely an illusion produced by
the cleavage ; but I determined to examine
it more fully on my return. In advancing
towards Sallenches, the road passes through
the lower part of the great calcareous formations
of Savoy. It consists of a vast
thickness of a dark argillaceous limestone,
in very thin strata, alternating with thicker
beds of grey limestone. * Near St. Martin,
beds of dark bituminous and argillaceous
schist, make their appearance under the
mountain on the left, called the Aguille de
Varons ; this terminates a band of calcareous
strata, 100 miles in breadth. At
St. Martin the river turns more west-
* In the Swiss Alps, this limestone is frequently combined
with such a large portion of argillaceous and siliceous
earth, as nearly to approach to the character of
hoi'nstone.
2