ing localities, were
surprised by a confused noise, mingled with detonations resembling the
firing of artillery. The phenomena commenced between ten and eleven
o'clock in the morning, and soon acquired such intensity as to cause
general alarm. The detonations were accompanied by tremblings of the
ground, of buildings and various objects contained in dwellings; but it
was generally admitted that these did not proceed from earthquake
shocks, but from atmospheric vibrations. No deviation of the magnetic
needle was observed at the Meteorological Institute of Batavia; but a
vertical oscillation was apparent, and persons who listened with the ear
placed on the ground, even during the most violent detonations, could
hear no subterranean noise whatever. It became clear that the sounds
came from some volcano burst into activity; but it is strange that for
two whole days it remained uncertain what was the particular volcano to
which the phenomena were to be referred. The detonations appeared,
indeed, to come from the direction of Krakatoa; but from Serang, Anjer,
and Merak, localities situated much nearer Krakatoa than Batavia, the
telegraph announced that neither detonations nor atmospheric vibrations
had been perceived. The distance between Batavia and Krakatoa is
ninety-three English miles. The doubts thus experienced were, however,
soon put to rest by the arrival of an American vessel under the command
of A. R. Thomas, and of other ships which hailed from the straits of
Sunda. From their accounts it was ascertained that in the direction of
Krakatoa the heavens were clouded with ashes, and that a grand column of
smoke, illumined from time to time by flashes of flame, arose from above
the island. Thus after a repose of more than two hundred years, "the
peaceable isle of Krakatoa, inhabited, and covered by thick forests, was
suddenly awakened from its condition of fancied security."

[Illustration: Fig. 36.--Section from Verlaten Island through Krakatoa,
to show the outline before and after the eruption of August, 1888. The
continuous line shows the former; the dotted line and shading, the
latter; from which it will be observed that the original island has to a
large extent disappeared. The line of section is shown in Fig. 35.]

(_c._) _Form and Appearance of the Island before the Eruption of
1883._--From surveys made in 1849 and 1881, it would appear that the
island of Krakatoa consisted of three mountains or groups of mountain