that which has been imagined to extend
through a large part of Central Asia to the Azores, that is to say,
from China and Tartary through Lake Aral and the Caspian to the
Caucasus, and the countries bordering the Black Sea, then again through
part of Asia Minor to Syria, and westward to the Grecian Islands,
Greece, Naples, Sicily, the southern part of Spain, Portugal and the
Azores. Respecting the eastern extremity of this line in China, we have
little information, but many violent earthquakes are known to have
occurred there. The volcano said to have been in eruption in the seventh
century in Central Tartary is situated on the northern declivity of the
Celestial Mountains, not far distant from the large lake called
Issikoul; and Humboldt mentions other vents and solfataras in the same
quarter, which are all worthy of notice, as being far more distant from
the ocean (260 geographical miles) than any other known points of
eruption.

We find on the western shores of the Caspian, in the country round Baku,
a tract called the Field of Fire, which continually emits inflammable
gas, while springs of naphtha and petroleum occur in the same vicinity,
as also mud volcanoes. Syria and Palestine abound in volcanic
appearances, and very extensive areas have been shaken, at different
periods, with great destruction of cities and loss of lives. Continual
mention is made in history of the ravages committed by earthquakes in
Sidon, Tyre, Berytus, Laodicea, and Antioch, and in the Island of
Cyprus. The country around the Dead Sea appears evidently, from the
accounts of modern travellers, to be volcanic. A district near Smyrna,
in Asia Minor, was termed by the Greeks Catacecaumene, or "the burnt
up," where there is a large arid territory, without trees, and with a
cindery soil.[483] This country was visited in 1841 by Mr. W. J.
Hamilton, who found in the valley of the Hermus perfect cones of scoriae,
with lava-streams, like those of Auvergne, conforming to the existing
river-channels, and with their surface undecomposed.[484]

_Grecian Archipelago._--Proceeding westwards, we reach the Grecian
Archipelago, where Santorin, afterwards to be described, is the grand
centre of volcanic action.

It was Von Buch's opinion that the volcanoes of Greece were arranged in
a line running N. N. W. and S. S. E., and that they afforded the only
example in Europe of active volcanoes having a linear direction; but M.
Virlet, on the contrary, announces a