514 
countries, manifest that mountains which 
seem to announce an approaching fall, 
by a too great inclination of their layers, 
and by a want of unity in their parts, 
do not form flakes capable of laying waste 
on a sudden the neighbouring country, 
if they do not vary in their state of ag- 
gregation and in their composition. 
hese undoubtedly produce calcareous 
dribblings, but their fall in general is 
successive and almost regular; we can 
daily obseive the effects, and are able 
before-hand to shelter ourselves 
them; thus the frequent decompositions 
which have happened in Mont Blanc, 
and the steep hill near it, have not been 
attended with any serious catastrophe to 
the inhabitants of that country. 
But if the composition of a mountain 
varies, if one or more hard and incimed 
layers succeed layers, which are tender 
and susceptible of being decomposed 
by water, the hard layers remain en- 
tire whilst that which is below wastes 
away. In consequeice of this waste a 
space totally void, or fuled with soft and 
incoherent matter, forms itself in the 
interior of the mountain. The upper 
layer being whole, but wauating 
of support, separates and sinks down at 
once in all points. It takes the place of 
the decomposed layer, and rolls to the 
foot of the mountain with a velocity pro- 
portionate to its degree of inclination, 
and to the motion acquired in the act of 
sinking. Such is nearly a sketch of is 
causes which produced the fall of th 
Diablerets, of Mount Chede near ee 
voz, and lastly of Mount Rufh, or Rufli- 
berg. 
This mountain, which is also called 
Rossberg, or Rosenberg, contains several 
parishes and estates; but these divisions 
are arbitrary, and not determined by any 
natural cut or division; that the names of 
Gnippe, Pee Steinerberg, and 
Rossberg, which have been given, with 
certain relations to the drifted mountain, 
are only different pastures of Rufiiberg, 
through which the drifted soap: hare 
passed. Besides, this last name 4s 
adopted i in preference to is of Ross- 
berg, lest it should be taken for Rotz- 
berg, a mountain of a very different 
appearance in the neighbourhood of 
Stantz. 
Rufiberg, eae to M. Ebel, is 
elevated eight hundred and six. toises 
above the sea,and five hundred and eighty- 
Bix tolses hoes the lake of Zug, or the 
lower part of the vale of Arth, into which 
this mountaim is partly fallen, ‘his vale, 
2 
ES . 
from ' 
a point» 
Account of the Fall of Ruffiberg in Switzerland. 
pile I, 
rich in pasture, is 2 league and a half 
length, and a quarter of faleaguein ees, 
at its western extremity towards Arth, a 
village situated on the border of the lake 
of Zug, and half a league at its opposite 
extremity towards the lake of Lowertz. 
Rutiberg is composed of layers of 
mixt stone, ane layers of freestone, whieh 
descend towards the bottom of the vailey 
of Arth, in a direction parallel to the ° 
slope of the mountain, and making an 
inclined angle of twenty-five degrees. 
The similarity that predominates in 
the composition and arrangement of Rigi 
and Ruthberg, led MM. Ebel,. and 
Escher, to suppose that these two moun- 
tains were formerly umted; for they are 
both composed. of stones, rounded by 
the action of water, and ‘of sand unit- 
ed by a cement partly calcareous and 
partly argillaceous, which is very often of 
a red colour. This cement, which is 
pretty hard, becomes destroyed i in time 
by the action of the air and of water, 
and the surface of the rock then has 
the appearance of a worn pavement. 
The pebbies of which it is formed, are 
chiefly of a yellowish green, and have 
rough and compact fracture of second- 
ary calcareous stones, apparently without 
any petrifactions. Here are also found 
secondary petrosilex, quartz, red j Jasper, 
reddish free-stone, and lastly granite ; 
but the last is scarce, always of a red 
colour, and might be casily mistaken for 
porpbyry. It is remarkable that all 
these stones bear no relation to the 
stones of the neighbouring mountains 
which are calcareous, blue, and have a 
lamellated or saline grain; and it-is like- 
wise singular that in bulk they never ex- 
ceed seven or eight inches square, 
The revolution which has heaped into 
this place such an enormous quantity o 
pebbles, rolied probably from a distance, 
has been followed by a subsequent revo- 
lution, which has brought upon these 
mixtures, and into the ‘bottom of the 
vale, large blocks of granite, similar to 
those found on Jura and Saleve. Similar 
ones are to be met with on Mount Rigi, 
even at the height of two hundred toises 
above the lake of Lucerne, in ascending 
this mountain on the side of Weggis, 
Some are also to be seen on Ruffiberg, at 
the height.of eighty toises between the 
village of St. Anne, and the hamlet of 
Buachen, near the lake of Lowertz. They 
are here so accumulated, as to exclude 
every other kind of stones, and it would 
be iniposs! ible not €o think one’s self on a 
soil purely granitic, were one uot diverted 
from 
