published
by order of the Governor-General of the Netherland Indies (1886). See
also an Article by Sir R. S. Ball in the _Contemporary Review_ for
November, 1888.

[2] Verbeek, _loc. cit._, p. 4.

[3] The account of this eruption is a free translation from Verbeek.

[4] Verbeek, _loc. cit._, p. 160.

[5] Judd, _Rep. R. S._

[6] A fuller account by Prof. Judd will be found in the _Report of the
Royal Society_, p. 14. Several vessels at anchor were driven ashore on
the straits owing to the strong wind which arose.

[7] Judd, _Report_, p. 21.

[8] _Report_, Part ii.

[9] In this eruption, 36,380 human beings perished, of whom 37 were
Europeans; 163 villages (_kampoengs_) were entirely, and 132 partially,
destroyed.--Verbeek, _loc. cit._, p. 79.

[10] Verbeek, _loc. cit._, p. 144-5. The dust put a girdle round the
earth in thirteen days.

[11] Verbeek, _loc. cit._, p. 30.

CHAPTER II.

EARTHQUAKES.

_Connection of Earthquakes with Volcanic Action._--The connection
between earthquake shocks and volcanic eruptions is now so generally
recognised that it is unnecessary to insist upon it here. All volcanic
districts over the globe are specially liable to vibrations of the
crust; but at the same time it is to be recollected that these movements
visit countries occasionally from which volcanoes, either recent or
extinct, are absent; in which cases we may consider earthquake shocks to
be abortive attempts to originate volcanic action.

(_a._) _Origin._--From the numerous observations which have been made
regarding the nature of these phenomena by Hopkins, Lyell, and others,
it seems clearly established that earthquakes have their origin in some
sudden impact of gas, steam, or molten matter impelled by gas or steam
under high pressure, beneath the solid crust.[1] How such impact
originates we need not stop to inquire, as the cause is closely
connected with that which produces volcanic eruptions. The effect,
however, of such impact is to originate a wave of translation through
the crust, travelling outwards from the point, or focus, on the surface
immediately over the point of impact.[2] These waves of translation can
in some cases be laid down on a map, and are called "isoseismal curves,"
each curve representing approximately an equal degree of seismal
intensity; as shown on the chart of a part of North America affected by
the great Charleston earthquake. (Fig. 37.) Mr. Hopkins has shown that
the earthqua