s
(Figs. 35, 36); the southern formed by the cone of Rakata (properly so
called), rising with a scarped face above the sea to a height of over
800 metres (2,622 feet). Adjoining this cone, and rising from the centre
of the island, came the group of Danan, composed of many summits,
probably forming part of the _enceinte annulaire_ of a crater. And near
the northern extremity of the isle, a third group of mammelated heights
could be recognised under the general name of Perboewatan, from which
issued several obsidian lava-flows, with a steep slope; these dated back
perhaps to the period of the first known eruption of 1680. This large
and mountainous island as it existed at the beginning of May, 1883, has
been entirely destroyed by the terrible eruptions of that year, with the
exception of the peripheric rim (composed of the most ancient of the
volcanic rocks, andesite), of which Verlaten Island and Rakata formed a
part, and one very small islet, which is noted on the maps as "rots"
(rock), and on the new map of the Straits of Sunda of the Dutch Navy as
that of "Bootsmansrots."[4]

As shown by the map in the Report of the Royal Society, the group of
islands which existed previous to 1883 were but the unsubmerged portions
of one vast volcanic crater, built up of a remarkable variety of lava
allied to the andesite of the Java volcanoes, but having a larger
percentage of silica, and hence falling under the head of
"enstatite-dacite."[5] That these volcanic rocks are of very recent
origin is shown by the fact, ascertained by Verbeek, that beneath them
occur deposits of Post-Tertiary age, and that these in turn rest on the
Tertiary strata which are widely distributed through Sumatra, Java, and
the adjoining islands. According to the reasoning of Professor Judd, the
Krakatoa group at an early period of its history presented the form of a
magnificent crater-cone, several miles in circumference at the base,
which subsequent eruptions shattered into fragments or blew into the
air in the form of dust, ashes, and blocks of lava, while the central
part collapsed and fell in, leaving a vast circular ring like the
ancient crater of Somma (see Fig. 6, p. 43), and he supposes the former
eruptions to have been on a scale exceeding in magnificence those which
have caused such world-wide interest within the last few years.

(_d._) _Eruption of 26th to 28th of August._--It was, as we have seen,
in the month of May that, in the language of Che