st end of Timor to the west end of Java. These modern
calcareous strata are often white and chalk-like, sometimes 1000 feet
and upwards above the sea, regularly stratified in thick horizontal
beds, and they show that there has been a general elevation of these
islands at a comparatively modern period.[480]

The same linear arrangement which is observed in Java holds good in the
volcanoes of Sumatra, some of which are of great height, as Berapi,
which is more than 12,000 feet above the sea, and is continually
smoking. Hot springs are abundant at its base. The volcanic line then
inclines slightly to the northwest, and points to Barren Island, lat.
12 degrees 15 minutes N., in the Bay of Bengal. This volcano was in
eruption in 1792, and will be described in the twenty-sixth chapter. The
volcanic train then extends, according to Dr. Macclelland, to the island
of Narcondam, lat. 13 degrees. 22 minutes N., which is a cone seven or
eight hundred feet high, rising from deep water, and said to present
signs of lava currents descending from the crater to the base.
Afterwards the train stretches in the same direction to the volcanic
island of Ramree, about lat. 19 degrees. N., and the adjoining island of
Cheduba, which is represented in old charts as a burning mountain. Thus
we arrive at the Chittagong coast, which in 1762 was convulsed by a
tremendous earthquake (see chap. 29).[481]

To enumerate all the volcanic regions of the Indian and Pacific oceans
would lead me far beyond the proper limits of this treatise; but it will
appear in the last chapter of this volume, when coral reefs are treated
of, that the islands of the Pacific consist alternately of linear groups
of two classes, the one lofty, and containing active volcanoes, and
marine strata above the sea-level, and which have been undergoing
upheaval in modern times; the other very low, consisting of reefs of
coral, usually with lagoons in their centres, and in which there is
evidence of a gradual subsidence of the ground. The extent and direction
of these parallel volcanic bands have been depicted with great care by
Darwin in his map before cited (p. 351).

The most remarkable theatre of volcanic activity in the Northern
Pacific--or, perhaps, in the whole world--occurs in the Sandwich
Islands, which have been admirably treated of in a recent work by Mr.
Dana.[482]

_Volcanic region from central Asia to the Azores._--Another great region
of subterranean disturbance is