840 



VOLCANOES. 



( )t thew great regions, that of the Andes is one of 

 the best defined. Commencing southward, at least 

 in Chile, at the forty-sixth degree of south latitude, 

 it proceeds north-ward to the twenty-seventh de- 

 gree, forming an uninterrupted line of volcanoes. 

 The Chilean volcanoes rise up through granitic 

 mountains. Villarica, one of the principal, con- 

 tinues burning without intermission, and is so high, 

 that it may be distinguished at the distance of 150 

 miles. A year never passes in this province with- 

 out some slight shocks of earthquakes ; and about 

 once in a century, or oftener, tremendous convul- 

 sions occur, by which the land has been shaken 

 from one extremity to the other, and continuous 

 tracts, together with the bed of the Pacific, have 

 been raised permanently from one to twenty feet 

 above their former level. Hot springs are numer- 

 ous in this district, and mineral waters of various 

 kinds. Pursuing our course northward, we find in 

 Peru only one active volcano as yet known ; but 

 the province is so subject to earthquakes, that 

 scarcely a week passes without a shock ; and many 

 of these have been so violent as to create great 

 changes of the surface. Farther north, we find, in 

 the middle of Quito, where the Andes attain their 

 greatest elevation, Tunguragua, Cotopaxi, Antisana 

 and Pichincha, the three former of which not unfre- 

 quently emit flames. From the first of these, a 

 deluge of mud descended in 1797, and filled valleys, 

 1000 feet wide, to the depth of 600 feet, forming 

 barriers, whereby rivers were dammed up, and lakes 

 occasioned. Earthquakes have, in the same pro- 

 vince, caused great revolutions in the physical fea- 

 tures of the surface. There are three volcanoes 

 farther north, in the province of Pasto, and three 

 others in that of Popayan. In the provinces of 

 Guatemala and Nicaragua, which lie between the 

 isthmus of Panama and Mexico, there are no less 

 than twenty-one active volcanoes. This great vol- 

 canic chain, after having pursued its course for 

 several thousand miles from south to north, turns 

 off in a side direction in Mexico, and is prolonged 

 in a great plateau, between the eighteenth and 

 twenty-second degrees of south latitude. The 

 plateau in question owes its present, form to the 

 circumstance of an ancient system of valleys, in a 

 chain of primary mountains, having been filled up, 

 to the depth of many thousand feet, with various 

 volcanic products. Five active volcanoes traverse 

 Mexico from west to east; viz. Tuxtla, Orizaba, 

 Popocatepetl, Jorullo and Colima. Jorullo, which 

 is in the centre of the great plateau, is no less than 

 forty leagues from the ocean, which shows that the 

 proximity of the sea is not a necessary condition, 

 although certainly a very general characteristic, of 

 the position of active volcanoes. The extraordi- 

 nary eruption of this mountain in 1759 will be 

 described in the sequel. To the north of Mexico 

 there are three, or according to some, five volcanoes, 

 in the peninsula of California. In the year 1812, 

 violent earthquakes convulsed the valley of the 

 Mississippi at New Madrid, for the space of three 

 hundred miles in length. As this happened exactly 

 at the same time as the great earthquake of Carac- 

 cas, it is probable that these two points are parts of 

 one continuous volcanic region ; for the whole cir- 

 cumference of the intervening Caribbean sea must 

 be considered as a theatre of earthquakes and vol- 

 canoes. ' On the north lies the island of Jamaica, 

 which, with a tract of the contiguous sea, has often 

 experienced tremendous shocks ; and these are fre- 

 quent along a line extending from Jamaica to St 



Domingo and Porto Rico. On the south of the 

 same basin, the shores and mountains of Columbia 

 are perpetually convulsed. On the west is the vol- 

 canic chain of Ouatimala and Mexico, and on the 

 east, the West Indian isles, where, in St Vincent's 

 and Guadaloupe, are active vents. Thus it will be 

 seen that volcanoes and earthquakes occur, unin- 

 terruptedly, from Chile to the north of Mexico; and 

 it seems probable, that they will hereafter be found 

 to extend, at least, from cape Horn to California. 

 In regard to the eastern limits of the region, they 

 lie deep beneath the waves of the Pacific, and must 

 therefore continue unknown to us. On the west, 

 they do not appear, except where they include the 

 West Indian islands, to be prolonged to a great dis- 

 tance; for there seem to be no indications of vol- 

 canic disturbances in Guiana, Brazil and Buenos 

 Ayres. On an equal, if not a still grander scale, is 

 another continuous line of volcanic action, which 

 commences on the north, with the Aleutian isles in 

 Russian America, and extends first in an easterly 

 direction for nearly two hundred miles, and south- 

 ward, without interruption, throughout a space of 

 between sixty and seventy degrees of latitude, to 

 the Moluccas, and then branches off in different 

 directions both towards the east and north-west. 

 The northern extremity of this volcanic region is 

 the peninsula of Alaska, in about the fifty-fifth de- 

 gree of latitude. Thence the line is continued, 

 through the Aleutian or Fox islands, to Kamts- 

 chatka, in the southern extremity of which there 

 are seven active volcanoes, which, in some erup- 

 tions, have scattered ashes to immense distances. 

 The Kurile chain of isles constitutes the prolonga- 

 tion of the range in a southern direction ; the line 

 is then continued to the south-west in the great 

 island of Jesso, where there are active vents. Be- 

 tween the Japanese and Philippine islands, the com- 

 munication is preserved by several small insular 

 vents. The line is then prolonged through Sanguir, 

 and the north-eastern extremity of Celebes, to the 

 Moluccas. 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. In the vol- 

 canoes of Sumatra, the same linear arrangement is 

 preserved. In another direction, the volcanic range 

 is prolonged through Borneo, Celebes, Banda, New 

 Guinea; and farther eastward in New Britain, New 

 Ireland, and various parts of the Polynesian archipe- 

 lago. The Pacific ocean, indeed, seems, in equatorial 

 latitudes, to be one vast theatre of igneous action ; 

 and its innumerable archipelagoes, such as the New 

 Hebrides, Friendly islands, and Georgian islands, 

 are all composed either of coralline limestones or 

 volcanic rocks, with active vents here and there 

 interspersed. In the old world, the volcanic region 

 extends from east to west for the distance of about 

 1000 miles, from the Caspian sea to the Azores, 

 including within its limits the greater part of the 

 Mediterranean and its most prominent peninsulas. 

 From south to north, it reaches from about the 

 thirty-fifth to the forty-fifth degree of latitude. 

 Its northern boundaries are Caucasus, the Black 

 sea, the mountains of Thrace, Transylvania and 

 Hungary, the Austrian, Tyrolian and Swiss Alps, 

 the Cevennes and Pyrenees, with the mountains 

 which branch off from the Pyrenees westward, to 

 the north side of the Tagus. Its western limits 

 are the ocean ; but it is impossible to determine 

 how far it may be prolonged in that direction ; 

 neither can we assign with precision its extreme 



