Hot springs are numerous in this district, ing Caribbean sea must be considered as and mineral waters of various kinds. a theatre of earthquakes and volcanoes. Pursuing our course northward, we find On the north lies the island of Jamaica, in Peru only one active volcano as yet which, with a tract of the contiguous sea, known; but the province is so subject to has often experienced tremendous shocks; earthquakes, that scarcely a week passes and these are frequent along a line exwithout a shock; and many of these have tending from Jamaica to St. Domingo been so violent as to create great changes and Porto Rico. On the south of the of the surface. Farther north, we find, in same basin, the shores and mountains of the middle of Quito, where the Andes Colombia are perpetually convulsed. On attain their greatest elevation, Tungura- the west is the volcanic chain of Guatigua, Cotopaxi, Antisana and Pichincha, mala and Mexico, and on the east, the the three former of which not unfre- West Indian isles, where, in St. Vincent's quently emit flames. From the first of and Guadaloupe, are active vents. Thus it these, a deluge of mud descended in will be seen that volcanoes and earth1797, and filled valleys, 1000 feet wide, to quakes occur, uninterruptedly, from Chile the depth of 600 feet, forming barriers, to the north of Mexico; and it seems whereby rivers were dammed up, and probable, that they will hereafter be found lakes occasioned. Earthquakes have, in to extend, at least, from cape Horn to the same province, caused great revolu- California. In regard to the eastern limtions in the physical features of the sur- its of the region,

they lie deep beneath face. There are three volcanoes farther the waves of the Pacific, and must therenorth, in the province of Pasto, and three fore continue unknown to us. On the others in that of Popayan. In the prov- west, they do not appear, except where inces of Guatimala and Nicaragua, which they include the West Indian islands, to lie between the isthmus of Panama and be prolonged to a great distance; for there Mexico, there are no less than twenty-one seem to be no indications of volcanic disactive volcanoes. This great volcanic turbances in Gujana, Brazil and Buenos chain, after having pursued its course for Ayres. On an equal, if not a still grandseveral thousand miles from south to er scale, is another continuous line of volnorth, turns off in a side direction in canic action, which commences on the Mexico, and is prolonged in a great plateau, north, with the Aleutian isles in Russian between the eighteenth and twenty-second America, and extends first in an easterly degrees of north latitude. The plateau direction for nearly two hundred miles, in question owes its present form to the and southward, without interruption, circumstance of an ancient system of throughout a space of between sixty and valleys, in a chain of primary mountains, seventy degrees of latitude, to the Moluchaving been filled up, to the depth of ma- cas, and then branches off in different ny thousand feet, with various volcanic directions both towards the east and products. Five active volcanoes traverse north-west. The northern extremity of Mexico from west to east ; viz. Tuxtla, this volcanic region is the peninsula of Orizaba, Popocatepetl, Jorullo and Coli- Alaska, in about the fifty-fifth degree of ma. Jorullo, which is in the centre of latitude. Thence the line is continued, the great plateau, is no less than forty through the Aleutian or Fox islands, to leagues from the ocean, which shows that Kamtschatka, in the southern extremity the proximity of the sea is not a necessa- of which there are seven active volcary condition, although certainly a very noes, which, in some eruptions, have general characteristic, of the position of scattered ashes to immense distances. active volcanoes. The extraordinary The Kurile chain of isles constitutes the eruption of this mountain in 1759 will prolongation of the range in a southern be described in the sequel. To the north direction; the line is then continued to of Mexico there are three, or, according to the south-west in the great island of Jesso, some, five volcanoes, in the peninsula of where there are active vents. Between California. In the year 1812, violent the Japanese and Philippine islands, the earthquakes convulsed the valley of the communication is preserved by several Mississippi at New Madrid, for the space small insular vents. The line is then of three hundred miles in length. As prolonged through Sanguir, and the this happened exactly at the same time as north-eastern extremity of Celebes, to the the great earthquake of Caraccas, it is Moluccas. Here a great transverse line probable that these two points are parts may be said to run from east to west. On of one continuous volcanic region; for the west, it passes through the whole of the whole circumference of the interven- Java, where there are thirty-eight largo

volcanic mountains. In the volcanoes leged existence of burning volcanoes in of Sumatra, the same linear arrangement that island shall be substantiated. Reis preserved. In another direction, the specting the volcanic system of Southern volcanic range is prolonged through Bor- Europe, it may be observed, that there is neo, Celebes, Banda, New Guinea ; and a central tract, where the greatest earthfarther eastward in New Britain, New quakes prevail, in which rocks are shatIreland, and various parts of the Polyne- tered and cities laid in ruins. On each sian archipelago. The Pacific ocean, in- side of this line of greatest commotion, deed, seems, in equatorial latitudes, to be there are parallel bands of country where one vast theatre of igneous action; and its the shocks are less violent. At a still innumerable archipelagoes, such as the greater distance, as in Northern Italy, New Hebrides, Friendly islands, and there are spaces where the shocks are Georgian islands, are all composed either much rarer and more feeble. Beyond of coralline limestones or volcanic rocks, these limits, again, all countries are liable with active vents here and there inter- to slight tremors at distant intervals of spersed. In the old world, the volcanic time, when some great crisis of subterregion 'extends from east to west for the ranean movement agitates an adjoining distance of about 1000 miles, from the Cas- volcanic region ; but these may be conpian sea to the Azores, including within sidered as mere vibrations, propagated its limits the greater part of the Medi- mechanically through the external crust terranean and its most prominent penin- of the globe, as sounds travel almost sulas. From south to north, it reaches to indefinite distances through the air. from about the thirty-fifth to the forty- Shocks of this kind have been felt in fifth degree of latitude. Its northern England, Scotland, Northern France and boundaries are Caucasus, the Black sea, Germany, particularly during the Lisbon the mountains of Thrace, Transylvania earthquake. and Hungary,--the Austrian, Tyrolian We shall now give some account of a and Swiss Alps,—the Cevennes and Pyr- few of the principal volcanic vents, disenees, with the mountains which branch persed through the great regions before off from the Pyrenees westward, to the described, and consider the composition north side of the Tagus. Its western and arrangement of their lavas and ejectlimits are the ocean; but it is impossible ed matter. From the first colonization to determine how far it may be prolonged of Southern Italy by the Greeks, Vesuin that direction; neither can we assign vius afforded no other indication of its with precision its extreme eastern limit

, volcanic character than such as the natsince the country beyond the Caspian and uralist might infer from the analogy of its sea of Aral is scarcely known. The structure to other volcanoes. These were southern boundaries of the region include recognised by Strabo. The ancient cone the most northern parts of Africa, and was of a very regalar form, terminating, part of the desert of Arabia. We may not, as at present, in two peaks, but with a trace, through the wbole of the area fattish summit, where the remains of an comprehended within these extensive ancient crater, nearly filled up, had left a limits, numerous points of volcanic erup, slight depression, covered in its interior tions, hot springs, gaseous emanations, and by wild vines, and with a sterile plain at other signs of igneous agency; while the bottom. On the exterior, the sides few tracts of any extent have been en- of the mountains were covered with fertirely exempi from earthquakes through- tile fields, richly cultivated, and at its out the last 3000 years. Besides the con- base were the populous

cities of Hercutinuous spaces of subterranean disturb- laneum and Pompeii. But the scene of ance, of which the outline has been repose was at length doomed to cease, given above, there are other disconnected and the volcanic fire was recalled to the volcanic groups, of which the geograph- main channel, which, at some former, unical extent is, as yet, imperfectly known. known period, had given passage to reAmong these may be mentioned Iceland, peated streams of melted lava, sand and which belongs, perhaps, to the same re- scoriæ. The first symptom of the revival gion as the volcano in Jan Mayen's island. of the energies of this volcano was the With these, also, part of the nearest coast occurrence of an earthquake, A. D. 63, of Greenland, which is sometimes shaken which did considerable injury to the cities by earthquakes, may be connected. The in its vicinity. From that time to the island of Bourbon belongs to another the- year 79, slight shocks were frequent; and atre of volcanic action, of which Mada- in the month of August of that year, they gascar probably forms a part, if the al- became more numerous and violent, till

they ended at length in an eruption. The day. The next eruption occurred in elder Pliny, who commanded the Roman 1306; between wbich era and 1631, there fleet, was then stationed at Misenum; was only one other (in 1500), and that a and, in his anxiety to obtain a near view slight one. During this interval, a memof the phenomena, he lost his life, being orable event occurred in the Phlegræan suffocated with sulphureous vapors. His fields—the sudden formation of a new nephew, the younger Pliny, remained at mountain in 1538. Frequent earthquakes Misenum, and has given us, in his Let- for two years preceding disturbed the ters, a lively description of the awful neighborhood of Pozzuoli ; but it was not

A dense column of vapor was until the twenty-seventh and twentyfirst seen rising vertically from Vesuvius, eighth of September, 1538, that they beand then spreading itself out laterally, so came alarming, when not less than twenthat its upper portion resembled the ty shocks were experienced in twenty-four head, and its lower, the trunk of the hours. At length, on the night of the pine, which characterizes the Italian twenty-ninth, two hours after sunset, a landscape. This black cloud was pierced, gulf opened between the little town of occasionally, by flashes of fire as vivid as Tripergola, which once existed on the lightning, succeeded by darkness more site of the Monte Nuovo, and the baths in profound than night. Ashes fell even its suburbs, which were much frequented. upon the ships at Misenum, and caused a A large fissure approached the town with shoal in one part of the sea, The ground a tremendous noise, and began to disrocked, and the sea receded from the charge pumice-stones, blocks of upmelted shores, so that many marine animals lava, and ashes mixed with water, and, were seen on the dry sand. The appear- occasionally, flames. The ashes fell in ances above described agree perfectly immense quantities, even at Naples. The with those witnessed in more recent erup- sea retired suddenly for two hundred tions, especially those of Monte Nuovo, yards, and a portion of its bed was left dry; in 1538, and of Vesuvius, in 1822. In and the whole coast from Monte Nuovo all times and countries, indeed, there is a to beyond Pozzuoli was upraised to the striking uniformity in the volcanic phe- height of many feet above the bed of the nomena; but it is most singular that Mediterranean, and has ever since rePliny, although giving a circumstantial mained permanently elevated. On the detail of so many physical facts, and en- third of October, the eruption ceased, so larging upon the manner of his uncle's that the hill Monte Nuovo, which is 440 death, and the ashes which fell when he feet above the level of the bay, and a mile was at Stabiæ, makes no allusion what- and a half in circumference at its base, ever to the sudden overwhelming of two and which was chiefly thrown up in a large and populous cities, Herculaneum day and a night, was accessible. The and Pompeii. (q. v.) Tacitus, the friend depth of its crater is 421 feet from the and contemporary of Pliny, when ad- summit of the hill, so that its bottom is verting, in general terms, to the convul- only nineteen feet above the level of the sion, says merely, that “ cities were swal- sea. For nearly a century after the birth lowed up or buried” (haustæ aut obrute of Monte Nuovo, Vesuvius still continuurbes. Hist. lib. i.). It does not appeared in a state of tranquillity. Bracini, who that, in the year 79, any lava flowed from visited Vesuvius not long before the erupVesuvius: the ejected substances appear tion of 1631, gives the following descripto have consisted entirely of sand and tion of its interior. The crater was five fragments of older lava. In 1036, the miles in circumference, and about one first eruption of flowing lava occurred. thousand paces deep. Its sides were covA second happened in 1049, and a third ered with brush wood, and at the bottom in 1138 ; after which a great pause en- there was a plain on which cattle grazed. sued of 168 years. During part of 1301, In the woody parts, wild boars frequently earthquakes had succeeded one another harbored. But at length these forests with fearful rapidity; and they terminated and grassy plains were suddenly conat last with the discharge of a lava sumed-blown into the air, and their stream from a point named ibe Campo del ashes scattered to the winds. In DecemArso, not far from the town of Ischia. ber, 1631, seven streams of lava poured This lava ran quite down to the sea—a at once from the crater, and overflowed distance of about two miles. Its surface several villages on the sides and at the is of a reddish-black color; and it is foot of the mountain. Great floods of almost as sterile, after a period of five mud were as destructive as the lava itcenturies, as if it had cooled down yester- self; for such (as often happens during these catastrophes) was the violence of mense volumes of aqueous vapor are the rains produced by the evolution of evolved from a crater during eruptions, aqueous vapor, that torrents of water de- and often for a long time subsequently to scended the cone, and, becoming charged the discharge of scoriæ and lava. These with impalpable volcanic dust, rolled vapors are condensed in the cold atmosalong loose ashes, acquiring such consist- phere surrounding, the high volcanic ency as to deserve the appellation of peak; and heavy rains are caused someaqueous lava. A brief period of repose times even in countries where, under ensued, which lasted only until the year other circumstances, such a phenomenon 1666, from which time to the present, is entirely unknown. The floods thus there has been a constant series of erup- occasioned sweep along impalpable dust tions, with rarely an interval of rest ex- and light scoriæ, till a current of mud is ceeding ten years. The modern lavas produced, which is often more dreaded of Vesuvius are characterized by a large than an igneous stream, from the greater proportion of augite. When they are velocity with which it moves. After composed of this mineral and feldspar, Vesuvius, the most authentic records rethey differ in composition but slightly late to Ætna, which rises, near the sea, in from many of the trap-rocks. (See Trap.) solitary grandeur, to the height of nearly They are often porphyritic, containing 15,000 feet, the mass consisting chiefly of disseminated crystals of augite, leucite, or volcanic matter ejected above the surface some other mineral, imbedded in a more of the water. The base of the cone is earthy base. These porphyritic lavas are eighty-seven miles. Ætna appears to often extremely compact. In the lava have been in activity from the earliest currents of central France (those of Vive- times of tradition. Thucydides informs rais), the uppermost portion, often forty us that between the colonization of Sicily feet or more in thickness, is an amor- by the Greeks and the commencement of phous mass passing downwards into lava, the Peloponnesian war (B. C. 431), three irregularly prismatic; and under this eruptions had occurred. A great eruption there is a foundation of regular and ver- occurred in the year 1669. The lava, after tical columns, in that part of the current having overflowed fourteen towns and vilwhich must have cooled most slowly. lages, some having a population of between A great variety of minerals are found in 3000 and 4000 inhabitants, arrived, at the lavas of Vesuvius and Somma. Au- length, at the walls of Catania. These had gite, leucite, feldspar, mica, olivine, spec- been purposely raised to protect the city; ular iron, idocrase, garnet and sulphur but the burning flood accumulated till it are most abundant. It is an extraordi- rose to the top of the rampart, which was nary fact, that, in an area of three square sixty feet in height, and then fell in a miles round Vesuvius, a greater number fiery cascade, and overwhelmed part of of mineral species have been found than the city. The wall, however, was not in any spot, of the same dimensions, on throwu down, but was discovered long the surface of the globe. Many of these afterwards by excavations made in the are peculiar to this locality. A small rock by the prince of Biscari ; so that part of the ejected matter, however, re- the traveller may now see the solid lava mains so near to the volcanic orifice. A curling over the top of the rampart, as if large portion of sand and scoriæ is borne still in the very act of falling. This great by the winds and scattered over the sur- current bad performed a course of fitteen rounding plains, or falls into the sea; and miles, before it entered the sea, where it much more is swept down by torrents was still 600 yards broad and 40 feet deep. into the deep during the intervals, often A gentleman of Catania, named Pappaprotracted for many centuries, between lardo, desiring to secure the city from the eruptions. These horizontal deposits of approach of the threatening torrent, went tufaceous matter become intermixed with out with a party of fitty men, whom he sediment of other kinds, and with shells and had dressed in skins to protect them from corals, and, when afterwards raised, form the heat, and armed with iron crows and rocks of a mixed character, such as tufas, hooks. They broke open one of the solid peperinos and volcanic conglomerates. walls which flanked the current near Besides the ejections which fall on the Belpasso, and immediately forth issued a cone, and that much greater mass which rivulet of melted matter, which took the finds its way gradually to the neighboring direction of Paternò; but the inhabitants sea, there is a third portion, often of no in- of that town, being alarmed for their considerable thickness, composed of allu- safety, took up arms, and put a stop to vions, spread over the valleys and plains, at further operations. In 1811, the great small distances from the volcano. Im- crater testified, by its violent detonations, that the lava had ascended to near the about equal in activity to the burning summit of the mountain, by its central mountains in other districts, we may then duct. A violent shock was then felt, and compute that there happen on the earth a stream broke out from the side of the about 2000 eruptions in the course of a cone, at no great distance from its apex. century, or about twenty every year, or Shortly after, other streams, to the num- one in eighteen days. However inconber of six, broke out in succession, still siderable, therefore, may be the superficial lower down the mountain, but all in the rocks, which the operations of fire prosame straight line. In 1819, three large duce on the surface, we must suppose mouths opened very near those which the subterranean changes now constantly were formed in the eruptions of 1811, in progress to be on the grandest scale. from which flames, red-hot cinders and The loftiest volcanic cones must be insigsand were thrown up, with loud explo- nificant when contrasted with the products sions. A few minutes afterwards, another of fire in the nether regions. One of the mouth opened below, from which flames earliest hypotheses to account for volcanic and smoke issued; and finally, a fifth, eruptions is that which attributes them to lower still, whence a. torrent of lava the eructations of a perpetual central fire, flowed, which spread itself, with great to which, however, the nature of the lava, velocity, over the valley Del Bove. This the method of its projection, and, above stream fowed two miles in the first twen- all, the known laws of the communication ty-four hours, and nearly as far in the of heat, are insurmountably opposed. The succeeding day and night. As the last sudden evolution of steam has also freexample of modern volcanic eruptions, quently been resorted to. They have also we shall mention that of Jorullo, in Mex- been referred to the ignition of beds of ico, in 1759. The plain, which was the coal; and Werner supposed that the fire site of the eruption, is thirty-six leagues thus produced fused the circumjacent from the sea, and, at the time of the rocks, and formed lava. Others have calleruption, was occupied by fertile fields of ed sulphur, pyrites, petroleum and bitusugar-cane and indigo. - In the month men to their aid, but have sought in vain of June, hollow sounds, of an alarming for the necessary supply of oxygen, withnature, were beard, and earthquakes suc- out which these combustibles could not ceeded each other for two months, until

, perform their required part; and, indeed, in September, flames issued from the if we grant an unlimited supply of that ground, and fragments of burning rocks. element, the projectile force--the vaporwere thrown to prodigious heights. Six still remains to be accounted for. Others volcanic cones, composed of scoriæ and have imagined a great depôt of electric fragmentary lava were formed on the line matter, pent up in certain submarine and of a chasm which ran in the direction subterranean caverns, and occasionally from north-north-east to south-south-west. sallying forth to fuse and blow up the The least of these cones was 300 feet in surrounding materials. The most plauheight; and Jorullo, the central one, was sible theory of volcanoes is that suggested elevated 1600 feet above the level of the by sir H. Davy, soon after he had dissea. A subsequent eruption of Jorullo covered the nature of the earthy and happened in 1819, accompanied by an alkaline bodies. Indeed, it enables us, in earthquake. The city of Guanaxuato, most cases, upon just principles of sound distant about 140 miles from Jorullo, was analogy, to explain their origin ; for lava covered with ashes, to the depth of six consists of earthy and alkaline bodies, inches, from this eruption. During the ejected in intense ignition; and it is assolast century, about fifty eruptions are re- ciated with vapor, with explosions of hycorded of the five European volcanoes, drogen gas, with the production of nitroVesuvius, Ætna, Volcano, Santorin and gen; and, in short, there is every concomIceland; but many beneath the sea, in the itant circuinstance to lead to the concluGrecian Archipelago, and near Iceland, sion, that there exist, in the bowels of the may, doubtless, have passed unnoticed. earth, masses of those highly inflammable If some of them produced no lava, others, metallic bodies, constituting the bases of on the contrary, like that of Skoptar Jo- the earths and alkalies; and these and kul, in 1783, poured out melted matter water are essential requisites for the profor five or six years consecutively. Now, duction of the phenomena that precede, if we consider the active volcanoes of accompany and follow the eruption of Europe to constitute about a fortieth part volcanoes : they may be referred to, as of those already known on the globe, and accounting for the earthquakes, the excalculate that, one with another, they are plosions and the gaseous products; and