ntaining within it a second crater, bounded by a black ledge with a
steep wall of basalt--a crater within a crater; and from the floor of
the inner crater, formed of molten basalt, in a seething and boiling
state, arise a large number of small cones and pyramids of lava, some
emitting columns of grey smoke, others brilliant flames and streams of
molten lava, presenting a wonderful spectacle, the effect of which is
heightened by the constant roaring of the vast furnaces below.[9]

[1] _Principles of Geology_, 11th edition, vol. ii. p. 48.

[2] Smyth, _Report on the Teneriffe Astronomical Experiment of 1856_.
Humboldt makes the elevation 12,090 feet. A beautiful model of the Peak
was constructed by Mr. J. Nasmyth from Piazzi Smyth's plans, of which
photographs are given by the latter.

[3] Daubeny, _loc. cit._, p. 460.

[4] _Iles Canaries_, p. 37.

[5] Daubeny, _loc. cit._, p. 426.

[6] Lister, "Notes on the Geology of the Tonga Islands," _Quart. Jour.
Geol. Soc._, No. 188, p. 590 (1891).

[7] Dana, _Characteristics of Volcanoes, with Contributions of Facts and
Principles from the Hawaiian Islands_. London, 1890.--Also, _Geology of
the American Exploring Expedition--Volcanoes of the Sandwich Islands_.

[8] Coan, _Amer. Jour. of Science_, 1853.

[9] W. Ellis, the missionary, has given a vivid description of this
volcano in his _Tour of Hawaii_. London, 1826.--Plans of the crater will
be found in Professor Dana's work above quoted.

PART II.

EUROPEAN VOLCANOES.

CHAPTER I.

VESUVIUS.

Having now dealt in a necessarily cursory manner with volcanoes of
distant parts of the globe, we may proceed to the consideration of the
group of active volcanoes which still survive in Europe, as they possess
a special interest, not only from their proximity and facility of
access, at least to residents in Europe and the British Isles, but from
their historic incidents; and in this respect Vesuvius, though not by
any means the largest of the group, stands the first, and demands more
special notice. The whole group rises from the shores of the
Mediterranean, and consists of Vesuvius, Etna, Stromboli, one of the
Lipari Islands, and Vulcano, a mountain which has given the name to all
mountains of similar origin with itself.[1] Along with these are
innumerable cones and craters of extinct or dormant volcanoes, of which
a large number have been thrown out on the flanks of Etna.

(_a._) _Prehistoric Ideas regardin