264 ACTION OF TORRENTS. 
There is one effect of the action of torrents which few tray- 
ellers on the Continent ave heedless enough to pass without 
notice. I refer to the elevation of the beds of mountain streams 
in consequence of the deposit of the débris with which they 
are charged. To prevent the spread of sand and gravel over 
and other like scenes in BERLEPSCH, Die Alpen, pp. 169 et segg., or in Stephen’s 
English translation, 
About an hour from Thusis, on the Spliigen road, ‘‘ opens the awful chasm 
of the Nolla which a hundred years ago poured its peaceful waters through 
smiling meadows protected by the wooded slopes of the mountains. But the 
woods were cut down and with them departed the rich pastures, the pride of« 
the valley, now covered with piles of rock and rubbish swept down from the 
mountains. This result is the more to be lamented as it was entirely com- 
passed by the improvidence of man in thinning the forests.”—MOoRELL, Seéen- 
tific Guide to Switzerland, p. 100.” 
The recent change in the character of the Mella—a river anciently so re- 
markable for the gentleness of its current that it was specially noticed by 
Catullus as flowing molli flumine--deserves more than a passing remark. This 
river rises in the mountain-chain east of Lake Iseo, and traversing the district 
of Brescia, empties into the Oglio after a course of about seventy miles. The 
iron-works in the upper valley of the Mella had long created a considerable 
demand for wood, but their operations were not so extensive as to occasion 
any very sudden or general destruction of the forests, and the only evil expe- 
rienced from the clearings was the gradual diminution of the volume of the 
river. Within the last thirty years, the superior quality of the arms mauu- 
factured at Brescia has greatly enlarged the sale of them, and very naturally 
stimula‘ed the activity of both the forges and of the colliers who supply them, 
and the hillsides have been rapidly stripped of their timber. Up to 1850, no 
destructive inundation of the Mella had been recorded. Buildings in great 
numbers had been erected upon its margin, and its valley was conspicuous for 
its rural beauty and its fertility. But when the denudation of the mountains 
had reached a certain point, avenging nature began the work of retribution. 
In the spring and summer of 1850 several new torrents were suddenly formed 
in the upper tributary valleys, and on the 14th and 15th of August in that 
year a fall of rain, not heavier than had been often experienced, produced a 
flood which not only inundated much ground never before overflowed, but 
destroyed a great number of bridges, dams, factories, and other valuable 
structures, and, whet was a far more serious evil, swept off from the rocks an 
incredible extent of soil, and converted one of the most beautiful valleys of 
the Italian Alps into a ravine almost as bare and as barren as the savagest 
gorge of Southern France. The pecuniary damage was estimated at many 
toillions of francs, and the violence of the catastrophe was deemed so extraor- 
