282 VOLCANIC ACTION. [SECT. xxvr. 



Islands on one hand ; and stretching quite across the Pacific 

 Ocean, through the Polynesian Archipelago, the New He- 

 brides, the Georgian and Friendly Islands, on the other. 

 Another chain begins with the Aleutian Islands, extends to 

 Kaintschatka, and from thence passes through the Kurile, 

 Japanese, and Philippine Islands, to the Moluccas, whence 

 it spreads with terrific violence through the Indian Archi- 

 pelago, even to the Bay of Bengal. Volcanic action may 

 again be followed from the entrance of the Persian Gulf to 

 Madagascar, Bourbon, the Canaries, and Azores. Thence 

 a continuous igneous region extends through about 1000 

 geographical miles to the Caspian Sea, including the Mediter- 

 ranean, and extending north and south between the 35th and 

 40th parallels of latitude ; and in central Asia a volcanic 

 region occupies 2500 square geographical miles. The vol- 

 canic fires are developed in Iceland in tremendous force ; and 

 the antarctic land recently discovered by Sir James Ross is 

 an igneous formation of the boldest structure, from whence 

 a volcano in high activity rises 12,000 feet above the perpetual 

 ice of these polar deserts, and within 19^ of the south pole. 

 Throughout this vast portion of the world the subterraneous 

 fire is often intensely active, producing such violent earth- 

 quakes and eruptions that their effects, accumulated during 

 millions of years, may account for many of the great geo- 

 logical changes of igneous origin that have already taken 

 place in the earth, and may occasion others not less remark- 

 able, should time that essential element in the vicissitudes 

 of the globe be granted, and their energy last. 



Mr. Lyell, who has shown the power of existing causes 

 with great ingenuity, estimates that on an average twenty 

 -eruptions take place annually in different parts of the world ; 

 and many must occur or have happened, even on the most 

 extensive and awful scale, among people equally incapable 

 of estimating their effects and of recording them. We 

 should never have known the extent of the fearful eruption 

 which took place in the island of Sumbawa, in 1815, but for 



