locality in which the eruptive phenomena were manifesting
themselves was nearly the same as that which formed
the theater of the celebrated eruption of 1669.
This locality overlooks an inclined plane which is
given up to cultivation, and in which are scattered,
at a short distance from the place of the eruption,
twelve villages having a total population of 20,000
inhabitants. On the second day the character,
of the eruption had become of a very alarming character.
New fissures showed themselves up to the vicinity of
Nicolosi, and the lava flowed in great waves over
the circumjacent lands. This seemed to indicate
a lengthy eruption; but, to the surprise of those interested
in volcanic phenomena, on the third day the eruptive
movement began to decrease, and, during the night,
stopped entirely. This was a very fortunate circumstance,
for this eruption would have caused immense damages.
It cannot be disguised, however, that the eruptive
attendants of this conflagration remain under conditions
such as to constitute a permanent danger for the neighboring
villages. It has happened, in fact, that in consequence
of the quick cessation of the eruption, those secondary
phenomena through which nature usually provides a
solid closing of the parasitic craters have not occurred.
So it is probable that when a new eruption takes place
it will be at the same point at which manifested itself
the one that has just abated.—La Nature
* * * *
Take an ordinary wine bottle and place it in front
of and within a few inches of a lighted candle.
Blow against the bottle with your mouth at about four
or six inches distant from it and in a line with the
flame. Very curiously, notwithstanding the presence
of the bottle and its interception of the current
of air, the candle will be immediately extinguished
as if there were no obstacle in the way. This
phenomenon is readily understood when we reflect that
the bottle receives the current of air on its polished
surface and divides it into two, one of which is guided
to the right and the other to the left. These
two currents, after separating and driving back the
surrounding air, meet again at the very spot at which
the flame is situated, and extinguish the candle.
[Illustration: MODE OF EXTINGUISHING A CANDLE
PLACED BEHIND A BOTTLE.]
It is evident that the experiment can be reproduced
by putting the candle behind a stove pipe, a cylinder
of glass or metal, a cylindrical tin box, or any other
object of the same form with a diameter greater than
that of a bottle, but not having a rough or angular
surface, since the latter would cause the current to
be lost in the surrounding air.
* * * *