In That Land Where Nature Has Covered Every Mountain And Every Valley With Her Marvels?

If we consider a burning crater only as an isolated phenomenon, if we be satisfied with merely examining the mass of stony substances which it has thrown up, the volcanic action at the surface of the globe will appear neither very powerful nor very extensive.

But the image of this action becomes enlarged in the mind when we study the relations which link together volcanoes of the same group; for instance, those of Naples and Sicily, of the Canary Islands,* of the Azores, of the Caribbee islands of Mexico, of Guatimala, and of the table-land of Quito; when we examine either the reactions of these different systems of volcanoes on one another, or the distance at which, by subterranean communication, they simultaneously convulse the earth. (I have already observed (Chapter 1.2) that the whole group of the Canary Islands rises, as we may say, above one and the same submarine volcano. Since the sixteenth century, the fire of this volcano has burst forth alternately in Palma, Teneriffe, and Lancerote. Auvergne presents a whole system of volcanoes, the action of which has now ceased; but in the middle of a system of active volcanoes, for instance, in that of Quito, we must not consider as an extinguished volcano a mountain, the crater of which is obstructed, and through which the subterraneous fire has not issued for ages. Etna, the Aeolian Isles, Vesuvius, and Epomeo; the peak of Teyde, Palma, and Lancerote; St. Michael, La Caldiera of Fayal, and Pico; St. Vincent, St. Lucia, and Guadaloupe; Orizava, Popocatepetl, Jorullo, and La Colima; Bombacho, the volcano of Grenada, Telica, Momotombo, Isalco, and the volcano of Guatimala; Cotopaxi, Tunguragua, Pichincha, Antisana, and Sangai, belong to the same system of burning volcanoes; they are generally ranged in rows, as if they had issued from a crevice, or vein not filled up; and, it is very remarkable, that their position is in some parts in the general direction of the Cordilleras, and in others in a contrary direction.)

The study of volcanoes may be divided into two distinct branches; one, simply mineralogical, is directed to the examination of the stony strata, altered or produced by the action of fire; from the formation of the trachytes or trap-porphyries, of basalts, phonolites, and dolerites, to the most recent lavas: the other branch, less accessible and more neglected, comprehends the physical relations which link volcanoes together, the influence of one volcanic system on another, the connection existing between the action of burning mountains and the commotions which agitate the earth at great distances, and during long intervals, in the same direction. This study cannot progress till the various epochs of simultaneous action, the direction, the extent, and the force of the convulsions are carefully noted; till we have attentively observed their progressive advance to regions which they had not previously reached; and the coincidence between distant volcanic eruptions and those noises which the inhabitants of the Andes very expressively term subterraneous thunders, or roarings.* (* Bramidos y truenos subterraneos.) All these objects are comprehended in the domain of the history of nature.

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