that the
cone of a volcano is liable to variations in height at different
periods, and a diminution of more than three hundred feet has occurred
during the course of a single eruption of AEtna, owing to the falling
of the cone of cinders into the crater. During the last sixty years,
however, the height of the mountain has been practically constant at
ten thousand eight hundred and seventy-four feet.

There are two cities, Catania and Aci Reale, and sixty-three towns or
villages on Mount AEtna. It is far more thickly populated than any
other part of Sicily or Italy. No less than 300,000 people live on the
mountain.

A remarkable feature of AEtna is the large number of minor cones which
are scattered over its sides. They look small in comparison with the
great mass of the mountain, but in reality some of them are of large
dimensions.

The best period for making the ascent of AEtna is between June and
September, after the melting of the winter snows, and before the
falling of the autumnal rains. In winter there are frequently nine or
ten miles of snow stretching from the summit downward, the paths are
obliterated, and the guides sometimes refuse to accompany travelers.
Moreover, violent storms often rage in the upper regions of the
mountain, and the wind acquires a force which it is difficult to
withstand, and is at the same time piercingly cold.

A list of the eruptions of AEtna from the earliest times has been given
by several writers. The first eruption within the historical period
probably happened in the seventh century B.C.; the second occurred in
the time of Pythagoras. The third eruption, which was in 477 B.C., is
mentioned by Thucydides, and it must have been the same eruption to
which Pindar and AEschylus allude. An eruption mentioned by Thucydides
happened in the year 426 B.C. An outburst of lava took place from
Monte di Moja, the most northerly of the minor cones of AEtna, in 396
B.C., and following the course of the river Acesines, now the
Alcantara, entered the sea near the site of the Greek colony of Naxos
(now Capo di Schiso). We have no record of any further eruption for
256 years, till the year 140 B.C. Six years later an eruption
occurred, and the same authorities mention an eruption in the year 126
B.C. Four years later Katana was nearly destroyed by a new eruption.
Another, of which we possess no details, occurred during the civil war
between Caesar and Pompey, 49 B.C. Livy speaks of an earthquak