MOUNTAIN SLIDES. 
267 
and covered to the depth of seventy feet, the town of Plurs in 
the valley of the Maira, on the night of the 4th of September, 
1618, sparing not a soul of a population of 2,430 inhabitants, 
is one of the most memorable of these catastrophes, and the 
fall of the Rossberg or Rufiberg, which destroyed the little town 
of Goldan in Switzerland, and 450 of its people, on the 2d of 
September, 1806, is almost equally celebrated. In 1771, ac¬ 
cording to Wessely, the mountain peak Piz, near Alleglie in 
the province of Belluno, slipped into the bed of the Cordevole, 
a tributary of the Piave, destroying in its fall three hamlets 
and sixty lives. The rubbish filled the valley for a distance 
of nearly two miles, and, by damming up the waters of the 
Cordevole, formed a lake about three miles long, and a hun¬ 
dred and fifty feet deep, which still subsists, though reduced 
to half its original length by the wearing down of its outlet.* 
On the 14th of February, 1855, the hill of Belmonte, a little 
below the parish of San Stefano, in Tuscany, slid into the val¬ 
ley of the Tiber, which consequently flooded the village to the 
depth of fifty feet, and was finally drained off by a tunnel. 
The mass of debris is stated to have been about 3,500 feet 
long, 1,000 wide, and not less than 600 high.f 
Such displacements of earth and rocky strata rise to the 
magnitude of geological convulsions, but they are of so rare 
occurrence in countries still covered by the primitive forest, so 
common where the mountains have been stripped of their 
native covering, and, in many cases, so easily explicable by 
the drenching of incohesive earth from rain, or the free admis¬ 
sion of water between the strata of rocks—both of which a 
coating of vegetation would have prevented—that we are jus¬ 
tified in ascribing them for the most part to the same cause as 
* Wessely, Die Oesterreichischen Alpenldnder und ihre Forste , pp. 125, 
126. Wessely records several other more or less similar occurrences in 
the Austrian Alps. Some of them, certainly, are not to he ascribed to the 
removal of the woods, but in most cases they are clearly traceable to that 
cause. 
t Bianohi, Appendix to the Italian translation of Mrs. Somerville’s 
Physical Geography, p. xxxvi. 
