OCR Text |
Show ·:a1s GEOGRAPiliCAL BOUNDARIES there are active volcanic vents, as also in Nipon, the principal of the Japanese group, where the number of burning mouhtains is very great; slight shocks of earthquakes being almost incessant, and violent ones experiehced at distant intervals. Between the Japanese and Philippine Islands, the communication is preserved by several small insular vents. Sulphur Island, in the Loo Choo archipelago, emits sulphureous vapour; and Formosa suffers greatly from earthquakes. In Luzon, the most northern and largest of the Philippirtes, are three active volcanos; Mindinao also was in eruption in 1764. The line is then prolonged through Sanguir and the northeastern extremity of Celebes, by Temate and Tidore, to the Moluccas, and, amongst the rest, Sumbawa. Here a great transverse line may be said to run from east to west. On the west it passes through the whole of Java, where there are thirty-eight large volcanic mountains, many of which continually discharge smoke and sulphureous vapours. In the volcanos of Sumatra, the same linear arrangement is preserved; but the line inclines gradually to the north-west in such a manner as to point to the active volcano in Barren Island in the Bay of Bengal, in about the twelfth degree of north latitude. In another direction the volcanic range is prolonged through Borneo, Celebes, Banda, and New Guinea; and farther eastward in New Britain, New Ireland, and various parts of the Polynesian archipelago. The Pacific Ocean, indeed, seems, in equatorial latitudes, to be one vast theatre of igneous action; and its innumerable archipelagos, such as the New Hebrides, Friendly Islands, and Georgian Isles, are all composed either of coralline limestones, or volcanic rocks with active vents here and there interspersed. The abundant production of carbonate of lime, in solution, would alone raise a strong presumption of the volcanic constitution of these tracts, even if there were not more positive proofs of igneous agency. If we now turn our attention to the principal region in the Old World, which, from time immemorial, has been agitated by earthquakes, and has given vent at certain points to subterranean fires, we find that it possesses the same general cha· racters. This l'egion extends from east to west for the dista~ce of about one thousand geographical miles, from the Casp1an Sea to the Azores; including within its limits the greater part r~r======~~~/)3'0 1./. 20 V ({]) lLCAIH <C JBAr'fll)) • .o/'th/' MOLUC'CA, cvu.b Su:NDA.. ISLANDS. |