STRANGE EFFECTS
Among the notable things which attended this eruption, it is recorded
that in Torre del Greco metallic and other substances exposed to
the current were variously affected. Silver was melted, glass became
porcelain, iron swelled to four times its volume and lost its texture.
Brass was decomposed, and its constituent copper crystallized in
cubic and octahedral forms aggregated in beautiful branches. Zinc was
sometimes turned to blende. During the eruption, the lip of the crater
toward Bosco Tre Case on the south east, fell in, or was thrown off, and
the height of that part was reduced 426 feet.
On the 17th, the sea was found in a boiling state 100 yards off the new
promontory made by the lava of Torre del Greco, and no boat could remain
near it on account of the melting of the pitch in her bottom. For nearly
a month after the eruption vast quantities of fine white ashes, mixed
with volumes of steam, were thrown out from the crater; the clouds
thus generated were condensed into heavy rain, and large tracts of the
Vesuvian slopes were deluged with volcanic mud. It filled ravines, such
as Fosso Grande, and concreted and hardened there into pumiceous tufa--a
very instructive phenomenon.
Immense injury was done to the rich territory of Somma, Ottajano and
Bosco by heavy rains, which swept along cinders, broke up the road and
bridges, and overturned trees and houses for the space of fifteen days.
There were few years during the nineteenth century in which Vesuvius did
not show symptoms of its internal fires, and at intervals it manifested
much activity, though not equaling the terrible eruptions of its past
history.
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