oned and in various other outbreaks, a wide field
of cultivated land, overwhelming many villages. The last considerable
eruption which yielded large quantities of lava was that of 1872,
which sent its tide for a distance of about six miles.

Since 1636 the eruptions of Vesuvius have steadily increased in
frequency, and, on the whole, diminished in violence. In the early
years of its history the great outbreaks were usually separated by
intervals of a century or more, and were of such energy that the lava
was mostly blown to dust, forming clouds so vast that on two occasions
at least they caused a midnight darkness at Constantinople, nearly
twelve hundred miles away. This is as if a volcano at Chicago should
completely hide the sun in the city of Boston. In the present state of
Vesuvius, the cone may be said to be in slight, almost continuous
eruption. The old central valley which existed before the eruption of
79, and continued to be distinct for long after that time, has been
filled up by a smaller cone, bearing a relatively tiny crater of vent,
the original wall being visible only on the eastern and northern parts
of its circuit, and here only with much diminished height. On the
western face the slope from the base of the mountain to the summit of
the new cone is almost continuous, though the trained eye can trace
the outline of Monte Somma--its position in a kind of bench, which is
traceable on that side of the long slope leading from the summit of
the new cone to the sea. The fact that the lavas of Vesuvius have
broken out on the southwestern side, while the old wall of the cone
has remained unbroken on the eastern versant, has a curious
explanation. The prevailing wind of Naples is from the southwest,
being the strong counter trades which belong in that latitude. In the
old days when the Monte Somma cone was constructed these winds caused
the larger part of the ashes to fall on the leeward side of the cone,
thus forming a thicker and higher wall around that part of the crater.

From the nature of the recent eruptions of Vesuvius it appears likely
that the mountain is about to enter on a second period of inaction.
The pipes leading through the new cone are small, and the mass of this
elevation constitutes a great plug, closing the old crater mouth. To
give vent to a large discharge of steam, the whole of this great mass,
having a depth of nearly two thousand feet, would have to be blown
away. It seems most likely t