"The mysterious terrors which hung over the spot. and the wild love of adventure, made some of the Spanish cavaliers desirous to attempt the ascent, which the natives declared no man could accomplish and live. Cortes encouraged them in the enterprise, willing to show the Indians that no achievement was above the dauntless daring of his followers. One of his captains, accordingly, Diego Ordaz, with nine Spaniards, and several Tlascalans, encouraged by their example, undertook the ascent. It was attended with more difficulty than had been anticipated.

"The lower region was clothed with a dense forest, so thickly matted, that in some places it was scarcely possible to penetrate it. It grew thinner, however, as they advanced, dwindling by degrees into a straggling stunted vegetation, till, at the height of somewhat more than 13,000 feet, it faded away altogether. The Indians, who had held on thus far; intimidated by the strange subterraneous sounds of the volcano, even then in a state of combustion, now left them. The track opened on a black surface of glazed volcanic sand and of lava, the broken fragments of which, arrested in its boiling progress in a thousand fantastic forms, opposed continual impediments to their advance. Amidst these, one huge rock, the Pico del Fraile, a conspicuous object from below, rose to the perpendicular height of 150 feet, compelling them to take a wide circuit. They soon came to the limits of perpetual snow, where new difficulties presented themselves, as the treacherous ice gave an imperfect footing, and a false step might precipitate them into the frozen chasms that yawned around. To increase their distress, respiration in these aerial regions became so difficult, that every effort was attended with sharp pains in the head and limbs. Still they pressed on, till, drawing nearer the crater, such volumes of smoke, sparks, and cinders were belched forth from its burning entrails, and driven down the sides of the mountain, as nearly suffocated and blinded them. It was too much even for their hardy frames to endure, and, however reluctantly, they were compelled to abandon the attempt on the eve of its completion. They brought back some huge icicles—a curious sight in those tropical regions—as a trophy of their achievement, which, however imperfect, was sufficient to strike the minds of the natives with wonder, by showing that with the Spaniards the most appalling and mysterious perils were only as pastimes. The undertaking was eminently characteristic of the bold spirit of the cavalier of that day, who, not content with the dangers that lay in his path, seemed to court them from the mere Quixotic love of adventure. A report of the affair was transmitted to the Emperor Charles V.; and the family of Ordaz was allowed to commemorate the exploit by assuming a burning mountain on their escutcheon.

"The general was not satisfied with the result. Two years after he sent up another party, under Francisco Montano, a cavalier of determined resolution. The object was to obtain sulphur to assist in making gunpowder for the army. The mountain was quiet at the time, and the expedition was attended with better success. The Spaniards, five in-number, climbed to the very edge of the crater, which presented an irregular ellipse at its mouth, more than a league in circumference. Its depth might be from 800 to 1000 feet. A lurid flame burned gloomily at the bottom, sending up a sulphureous steam, which, cooling as it rose, was precipitated on the sides of the cavity. The party cast lots, and it fell on Montano himself to descend in a basket into this hideous abyss, into which he was lowered by his companions to the depth of 400 feet! This was repeated several times, till the adventurous cavalier had collected a sufficient quantity of sulphur for the wants of the army."

The more tranquil state of the volcano in modern times having rendered the summit no longer so difficult of access as it was in those days, the ascent has been several times achieved—twice in 1827, and again in 1833 and 1834. The crater is now a large oval basin with precipitous walls, composed of beds of lava, of which some are black, others of a pale rose tint. At the bottom of the crater, which is nearly flat, are several conical vents, whence are continually issuing vapours of variable colour, red, yellow, or white. The beds of sulphur deposited in this crater are worked for economical purposes. Two snowy peaks tower above its walls.

Not less magnificent in its proportions is the volcano of Orizaba, which is nearly of the same height as Popocatepetl. It was very active about the middle of the sixteenth century, having had several great eruptions between 1545 and 1560; but since then it has sunk into comparative repose. This mountain was ascended by Baron Muller in 1856. A first attempt proved unsuccessful; but by passing a night in a grotto near the limit of perpetual snow, he was able on the following day, after a toilsome ascent, to reach the edge of the crater—not, however, till near sunset. His experiences, and the scene which was presented to his wondering gaze, he describes in the following terms:—

"I have achieved my purpose, and joy banishes all my griefs, but only for a moment; suddenly I fell to the ground, and a stream of blood gushed from my mouth.

"On recovering, I found myself still close to the crater, and I then summoned all my strength to gaze and observe as much as possible. My pen cannot describe either the aspect of those regions, or the impressions they produced on me. Here seemed to be the gate of the nether world, enclosing darkness and horror. What terrible power must have been required to raise and shiver such enormous masses, to melt them and pile them up like towers, at the very moment of their cooling and acquiring their actual forms!

"A yellow crust of sulphur coats in several places the internal walls, and from the bottom rise several volcanic cones. The soil of the crater, so far as I could see, was covered with snow, consequently not at all warm. The Indians however affirmed that, at several points, a hot air issues from crevices in the rocks. Although I could not verify their statement, it seemed to me probable; for I have often observed similar phenomena in Popocatepetl.

"My original intention of passing the night on the crater had for overpowering reasons become impracticable. The twilight which, in this latitude, as every one knows, is extremely short, having already begun, it was necessary to prepare for our return. The two Indians rolled together the straw mats which they had brought, and bent them in front so as to form a sort of sledge. We sat down upon these, and stretching out our legs, allowed ourselves to glide down on this vehicle. The rapidity with which we were precipitated increased to such a degree, that our descent was rather like being shot through the air, than any other mode of locomotion. In a few minutes we dashed over a space which it had taken us five hours to climb."

There are several of the West Indian islands of volcanic origin; and three of them—St. Vincent, Martinique, and Guadaloupe—contain active volcanoes. The most remarkable is the volcano of Morne- Garou, in St. Vincent, the eruptions from which have been particularly violent. In 1812 the ashes which it threw out were so great in quantity, and projected to so vast a height, that they were carried to a distance of two hundred miles in the teeth of the trade-wind. From Mount Pelee, in Martinique, there was an eruption in August 1851. La Soufriere, the volcano in Guadaloupe, is said to have been cleft in twain during an earthquake. Its activity has long been in a subdued state; but it is remarkable for its deposits of sulphur.



CHAPTER VIII.

Hawaii, Sandwich Islands—Crater of Kilauea—Its awful Aspect— Fiery Lake and Islands—Jets of Lava—Depth of Crater and Surface of Lake—Bank of Sulphur—Curious Rainbow—Mouna-Kaah and Mouna- Loa—Eruption of the Latter in 1840—Recent Eruption—Great Jet and Torrent of Lava—Burning of the Forests—Great Whirlwinds— Underground Explosions—Other Volcanoes in the Pacific.

Hawaii is well known in history as being the island where the celebrated navigator Captain Cook was killed. The name used to be written Owhyhee; but a better apprehension of the native pronunciation has led to its being altered into Hawaii. No one who visits it in the present day need be afraid of sharing the fate of poor Captain Cook; for the descendants of the savages who, in his time, inhabited the island, have now, through the labours of Christian missionaries, become a very decent sort of quiet, well- behaved Christian people.

Hawaii, which is the largest of a group called the Sandwich Islands, can boast of the greatest volcanic crater in the world. It is called sometimes Kirauea, sometimes Kilauea; for the natives seem not very particular about the pronunciation of their l and their r; but where one uses l another as pertinaciously employs r, while a third set use a sound between the two, as you may have heard some people do at home. Situated on the lower slopes of a lofty mountain called Mouna-Roa, or Loa (for there is the same dubiety about the l and the r here as in the former case), the crater of Kilauea is a vast plain between fifteen and sixteen miles in circumference, and sunk below the level of its borders to a depth varying from two hundred to four hundred feet—the walls of rock enclosing it being for the most part precipitous. The surface of the ground is very uneven, being strown with huge stones and masses of volcanic rock, and it sounds hollow under the tramp of the foot.

Towards the centre of the plain is a much deeper depression. Those who have ventured to approach it, and look down, describe it as an awful gulf, about eight hundred feet in depth, and presenting a most gloomy and dismal aspect. The bottom is covered with molten lava, forming a great lake of fire, which is continually boiling violently, and whose fiery billows exhibit a wild terrific appearance. The shape of the lake resembles the crescent moon; its length is estimated at about two miles, and its greatest breadth at about one mile. It has numerous conical islands scattered round the edge, or in the lake itself, each of them being a little subordinate crater. Some of them are continually sending out columns of gray vapour; while from a few others shoots up what resembles flame. It is, probably, only the bright glare of the lava they contain, reflected upwards. Several of these conical islands are always belching forth from their mouths glowing streams of lava, which roll in fiery torrents down their black and rugged sides into the boiling lake below. They are said sometimes to throw up jets of lava to the height of upwards of sixty feet. The foregoing woodcut can convey only an imperfect idea of this immense crater.



The outer margin of the gulf all round is nearly perpendicular. The height of the bounding cliffs is estimated at about four hundred feet above a black horizontal ledge of hardened lava, which completely encircles it, and beyond which there is a gradual slope down into the burning lake. The surface of the molten lava is at present between three and four hundred feet below this horizontal ledge; but the lava is said sometimes to rise quite up to this level, and to force its way out by forming an opening in the side of the mountain, whence it flows down to the sea. An eruption of this kind took place in 1859. On one side of the margin of the lake there is a long pale yellow streak formed by a bank of sulphur. The faces of the rocks composing the outer walls of the crater have a pale ashy gray appearance, supposed to be due to the action of the sulphurous vapours. The surface of the plain itself is much rent by fissures. It is said that the glare from the molten lava in the lake is so great as to form rainbows on the passing rain-clouds.

The entire Island of Hawaii is of volcanic origin; and besides this great crater it contains two other lofty mountains, whose summits are covered with snow, and whose height is estimated at fifteen or sixteen thousand feet above the level of the sea. The one is named Mouna-Kaah or Keah, the other is Mouna-Loa—the same on whose lower flanks the crater of Kilauea is situated. Mouna-Kaah has long been in a state of repose. So also was Mouna-Loa up to 1840, when it burst forth with great fury, and it has continued more or less in a state of activity ever since. There has been a grand eruption very lately, said by the natives to have been the greatest of any on record.

A new crater opened near the top, at a height of about ten thousand feet, and for three days a flood of lava poured down the north- eastern slope. After a pause of about thirty-six hours, there was opened on the eastern slope, about half way down the mountain, another crater, whence there rose an immense jet of liquid lava, which attained a height of about a thousand feet, and had a diameter of about a hundred feet. This jet was sustained for twenty days and nights; but during that time its height varied from the extreme limit of a thousand, down to about a hundred feet. The play of this fiery fountain was accompanied by explosions so loud as to be heard at the distance of forty miles. Nothing could surpass the awful grandeur of this jet, which was at a white heat when it issued from its source, but, cooling as it ascended into the air, it became of a bright blood red, which, as the liquid fell, deepened into crimson.

In a few days there was raised around this crater a cone of about three hundred feet in height, composed of the looser materials thrown out along with the lava. This cone continued to glow with intense heat, throwing out occasional flashes. The base of this cone eventually acquired a circumference of about a mile. But the fountain itself formed a river of glowing lava, which rushed and bounded with the speed of a torrent down the sides of the mountain, filling up ravines and dashing over precipices, until it reached the forests at the foot of the volcano. These burst into flames at the approach of the fiery torrent, sending up volumes of smoke and steam high into the air. The light from the burning forests and the lava together was so intense as to turn night into day, and was seen by mariners at a distance of nearly two hundred miles.

During the day the air throughout a vast extent was filled with a murky haze, through which the sun showed only a pallid glimmer. Smoke, steam, ashes, and cinders were tossed into the air and whirled about by fierce winds—sometimes spreading out like a fan, but every moment changing both their form and colour. The stream of lava from the fountain flowed to a distance of about thirty-five miles. The scene was altogether terrific—the fierce red glare of the lava—the flames from the burning trees—the great volumes of smoke and steam—the loud underground explosions and thunderings,— all combined to overpower the senses, and fill the mind with indescribable awe.

A remarkable volcanic chain runs along the northern and western margins of the Pacific Ocean. It embraces the Aleutian Islands, the peninsula of Kamtschatka, the Kurile, the Japanese, and the Philippine Islands. The most interesting are the volcanoes of Kamtschatka, in which there is an oft-renewed struggle between opposing forces—the snow and glaciers predominating for a while, to be in their turn overpowered by torrents of liquid fire.



CHAPTER IX.

Atolls, or Coral Islands—Their strange Appearance—Their Connexion with Volcanoes—Their Mode of Formation—Antarctic Volcanoes—Diatomaceous Deposits

To the southward of the Sandwich Islands, on the other side of the equator, there is a large group of islands in the Pacific, which have a very peculiar appearance. They are called Atolls or Coral Islands. Although not exactly of volcanic origin, yet the manner in which they are formed has some connexion with submarine volcanic action.

An atoll consists essentially of a ring of coral rocks but little elevated above the level of the sea, and having in its centre a lagoon or salt-water lake, which generally communicates by a deep narrow channel with the sea. The ring of rocks is flat on the surface, which is composed of friable soil, and sustains a luxuriant vegetation, chiefly of cocoa-nut palms. It is seldom more than half a mile in breadth between the sea and lagoon, sometimes only three or four hundred yards. The outer margin of the ring is the highest, and it slopes gradually down towards the lagoon; but on the outside of the ledge of rocks is a beach of dazzling whiteness, composed of powdered and broken coral and shells. The appearance they present is thus not less beautiful than singular. Some of these islands are of large size, from thirty to fifty miles long, and from twenty to thirty broad, but they are in general considerably smaller. Their most frequent form is either round or oval. The rocks composing them are all formed by different species of coral. The animal which constructs them is of the polyp tribe, and so small that it can be seen only under the higher powers of the microscope. It multiplies by means of buds like those of a tree, the individuals all combining to form a composite stony mass, which is called a polypidom. A number of such polypidoms growing close together form a coral reef. See woodcuts.



It was at one time supposed that these coral reefs were erected on the edges of the craters of submarine volcanoes, an opinion to which their annular form, and the lagoon in the centre, lent some countenance; but the vast size of some of them, united to several other particulars connected with them, threw great doubts over this supposition.

More recently it has been shown by Mr. Darwin that, while volcanic agency does perform a part in their formation, it is different from what had been formerly imagined. His supposition is, that these coral reefs were built round the coasts of islands which had once stood very much higher above water than they do now. He conceives that the bottom of the sea under them being very volcanic, and containing large collections of molten lava beneath a thin solid crust, the islands have gradually sunk down into the lava, until their central parts have become covered with a considerable depth of water. The central parts thus submerged, he imagines, form the lagoons in the middle of the islands, while the ring of coral reefs has gradually grown upwards, as the ground on which it rested sank downwards.



The corals thus rise to near the surface, but immediately on their being uncovered by the water they die, and the reef ceases to grow. Then the waves by their action break the upper part of it into pieces, which thus become heaped up by degrees on the remainder, until the mass attain so great a height that the sea can no longer wash over it. Thus the curious ring of land is gradually formed, and affords a nutritive soil, in which cocoa-nuts, on being cast ashore, germinate and grow to be large trees. Other seeds, wafted by the waves or carried by birds, also begin to grow, until the whole surface becomes covered with vegetation. Then comes man and builds his habitation upon those fertile spots, and finds in them an agreeable and convenient abode, well suited to those who are accustomed to live by fishing and other simple means.

You will thus perceive that the connexion between the atoll and the volcano consists in this—that while the coral builds up the reef, the volcano beneath ingulfs the island and causes it to sink down. In some instances, however, the volcano, after a while, reverses its action, and raises up the island with the reef upon it. In such cases, the coral reefs are seen standing out of the water, forming perpendicular cliffs several hundred feet in height. Then also the interior of the island becomes once more dry land, and that, too, of great fertility.



Almost due south of that region, in the Pacific, where the coral islands abound, but at a great distance from them, and considerably within the limits of the Antarctic zone, lies South Victoria. Here, in lat. 76 degrees S., Captain Ross discovered, in 1841, two volcanoes, which he called Erebus and Terror, after the names of his two ships. Of the former, which is the higher of the two, a view is given in the annexed woodcut. It is covered with perpetual snow from the bottom even to the tip of the summit. Nevertheless, it is continually sending forth vast columns of vapour, which glow with the reflection of the white hot lava beneath. These vapours ascend to a great height, more than two thousand feet above the top of the cone, which is itself twelve thousand feet above the level of the sea.

There is found in these frozen regions a remarkable botanical curiosity, having a certain connexion with volcanoes. The waters of the ocean, all along the borders of the icy barrier, produce in amazing abundance the family of water-plants named Diatomaceae. The Diatoms are so called from their faculty of multiplying themselves indefinitely by splitting into two; and so rapidly is this process performed, that in a month a single diatom may produce a thousand millions. The quantity found in the Antarctic regions is so immense that, between the parallels of 60 degrees and 80 degrees of south latitude, they stain the whole surface of the sea of a pale olive- brown tint. These plants, which are so minute as to be individually invisible, save under the higher powers of the microscope, have the curious property of encrusting themselves with a sheath, or shell, of pure silica. These shells remain after the death of the plant, and are as indestructible as flint. They are marvellous objects, both as respects the elegance of their forms and the beauty of their markings. So great is the accumulation of these shells at the bottom of the sea, that they have formed an immense bank 400 miles in length by 120 in breadth, between the 76th and 78th degrees of south latitude. One portion of this bank rests on the coast at the foot of Mount Erebus.

Now, it is remarkable that these microscopic shells of Diatoms are not unfrequently found in the ejections of volcanoes; while it is generally supposed that, in the case of those situated near the sea, eruptions are caused by the formation of explosive steam consequent on the access of sea-water to the reservoirs of molten lava lying underground. The proximity of this Diatomaceous bed to Mount Erebus would easily explain how these minute shells might be found abundant in the fine dust ejected from that volcano.



CHAPTER X.

Volcanoes of Java—Papandayang—Mountain Ingulfed—Great Destruction of Life and Property—Galoen-gong—Destructive Eruption—Mount Merapia—Great Eruption, with Hurricane—Another, very destructive—Mud Volcano Crater of Tankuban-Prahu—Island of Sumbawa—Volcano of Tomboro—Terrific Eruption—Timor—A Volcano quenches itself—Cleaving of Mount Machian—Sangir—Destructive Eruption—Bourbon.

One of the most marvellous volcanic regions in the world is that composed of the islands of the Malayan Archipelago in the Indian Ocean. They form a chain stretching from east to west, but curving up towards the north at the western extremity. The most easterly of the chain is Timor, the most westerly Sumatra.

The most interesting of the group is Java, which is almost entirely of volcanic origin, and contains no less than thirty-eight mountains of that conical form which indicates their having at one time or other been active volcanoes. Only a few of them, however, have been in activity in more recent times. The most remarkable eruption was that of the mountain named Papandayang, which occurred in 1772. During this convulsion the greater part of the mountain, which was formerly one of the largest in the island, was completely swallowed up in some great underground gulf.

On the night between the 11th and 12th of August of that year, the mountain appeared to be wholly enveloped in a remarkable luminous cloud. The inhabitants fled in consternation; but before they could all escape, the mountain began to totter, and the greater part of it tumbled down and disappeared. The crash with which it fell was dreadful, the noise resembling the discharge of volleys of artillery. Besides that part of the mountain which thus fell in, a large extent of ground in its neighbourhood was ingulfed. The space measured fifteen miles in length and six in breadth. The ground for many miles round this space was covered with immense quantities of ashes, stones, cinders, and other substances thrown out by the volcano. These were, on many parts of the surface, accumulated to the height of three feet; and even at the end of six weeks, the layers thus deposited retained so much heat as to render the mountain inaccessible. By this dreadful occurrence forty villages were destroyed, some ingulfed with the ground on which they stood, others buried under the loose materials which had been ejected. Not far short of three thousand of the inhabitants perished.

Another of the volcanoes of Java, called Galoen-gong, burst into eruption in 1822, commencing with a terrible explosion of stones, ashes, &c., followed by a stream of hot mud, which overspread a large tract of ground. This eruption proved still more fatal to human life, about four thousand persons having been destroyed.

So lately as September 1849, Mount Merapia, another volcano in this island, which had been supposed to be quite extinct, burst forth into an eruption, which lasted three days. It was accompanied by a violent hurricane. The bed of a river was filled up by the matter thrown out from the crater, and the destruction of property in crops, &c., was immense. Fortunately the inhabitants succeeded in making their escape, so that no lives were lost. A second eruption of this mountain however, in January 1864, was more disastrous, three hundred and fifty people having perished.

Java likewise contains a remarkable mud volcano. When viewed from a distance, there are seen to rise from it large volumes of vapour, like the spray from the billows dashing against a rocky shore, and there is heard a loud noise like distant thunder. On a nearer approach, the source of these phenomena is seen to be a hemispherical mound of black earth mixed with water, about sixteen feet in diameter, and which at intervals of a few seconds is pushed upwards by a force acting from beneath to a height of between twenty and thirty feet. It then suddenly explodes with a loud noise, scattering in every direction a quantity of black mud, which has a strong pungent smell resembling that of coal-tar, and is considerably warmer than the air. With the mud thus thrown out there has been formed around the mound a large perfectly level and nearly circular plain, about half a mile in circumference. The water mixed with the mud is salt, and the salt is separated from it by evaporation for economical purposes. During the rainy season the action of this mud volcano becomes more violent, the explosions are louder, and the mud is thrown to a greater height.

The crater of Tangkuban-Prahu, another of the volcanoes of Java, presents a remarkable appearance. On approaching its edge, nothing is seen but an abyss, from which dense clouds of vapour continually arise, with hideous sounds, like the steam rushing from the open valves of hundreds of steam-engines. This great abyss consists really of two craters, separated the one from the other by a narrow ridge of rock, to which it is possible to descend and view them both. Each of them is elliptical in form, and surrounded by a crater-wall. That of the western, which the natives call the poison-crater, is a rapid slope nearly a thousand feet in depth, and is densely covered with brushwood almost to the bottom. The flat floor of this deep basin is continually sending out vapours, and in its centre is a pool of boiling water of a sulphur yellow colour. The floor itself is nothing but a crust of sulphur full of rents and holes, whence vapours constantly arise. This crust covers a surface of boiling hot bitter water, and by breaking it beautiful crystals of sulphur may be obtained.

The eastern is called by the natives the king's-crater; its walls are only between five and six hundred feet in depth, and are perfectly bare from top to bottom. The surfaces of the rocks composing them are grayish white, an effect produced upon them by the action of the vapours, to which they are continually exposed. The bottom of this crater consists of mud mixed with sulphur; but round the edges are some stones and hard masses. These are the remnants of an eruption which took place from this crater in 1846, when there was thrown up a great mass of sulphurous boiling mud, accompanied by quantities of sand and stones. This mountain, therefore, seems to be also more of the nature of a mud volcano, than of one which throws out burning lava.

Nearly in a right line to the eastward of Java lies the Island of Sumbawa, in which stands the volcano of Tomboro, the most violent in its eruptions of any in the world. One of the most remarkable occurred in the year 1815, beginning on the 5th of April and continuing till the middle of July. Its effects were felt over an immense tract of country, embracing the Molucca Islands, Java, and portions of Celebes, Sumatra, and Borneo. The concussions produced by its explosions were sensible at a distance of a thousand miles all round; and their sound is said to have been heard even at so great a distance as seventeen hundred miles. In Java the day was darkened by clouds of ashes, thrown from the mountain to that great distance (three hundred miles), and the houses, streets, and fields, were covered to the depth of several inches with the ashes that fell from the air. So great was the quantity of ashes ejected, that the roofs of houses forty miles distant from the volcano were broken in by their weight. The effects of the eruption extended even to the western coasts of Sumatra, where masses of pumice were seen floating on the surface of the sea, several feet in thickness and many miles in extent.

From the crater itself there were seen to ascend three fiery columns, which, after soaring to a great height, appeared to unite in a confused manner at their tops. Ere long, the whole of the side of the mountain next the village of Sang'ir seemed like one vast body of liquid fire. The glare was terrific, until towards evening, when it became partly obscured by the vast quantities of dust, ashes, stones, and cinders thrown up from the crater. Between nine and ten o'clock at night the ashes and stones began to fall upon the village of Sang'ir, and all round the neighbourhood of the mountain. Then arose a dreadful whirlwind, which blew down nearly every house in the village, tossing the roofs and lighter parts high into the air. In the neighbouring sea-port the effects were even more violent, the largest trees having been torn up by the roots and whirled aloft. Before such a furious tempest no living thing could stand. Men, horses, and cattle were whirled into the air like so much chaff, and then dashed violently down on the ground. The sea rose nearly twelve feet above the highest tide- mark, sweeping away houses, trees, everything within its reach.

This whirlwind lasted about an hour, and then commenced the awful internal thunderings of the mountain. These continued with scarcely any intermission until the 11th of July, when they became more moderate, the intervals between them gradually increasing till the 15th of July, when they ceased. Almost all the villages for a long distance round the mountain were destroyed; and it is computed that nearly twelve thousand persons perished. By far the greatest part of this destruction was wrought by the violence of the whirlwind which accompanied the eruption.

Considerably to the eastward of Sumbawa lies the Island of Timor, in which there was for a long time a volcanic peak, whose perpetual fires served as a lighthouse to mariners navigating those seas. But in the year 1637 there took place a great eruption of the mountain, which ended in its being gobbled up whole and entire, leaving nothing behind it but a lake, in which its fires were quenched, and which now occupies its place.

To the north of Timor lie the Molucca Islands, several of which are volcanic. In one of them, named Machian, there occurred in the year 1646 an extraordinary event. A mountain was rent from top to bottom, sending out great columns of fire and dense vapours. The two parts now remain two distinct mountains.

In the Island of Sangir, another of the Moluccas, there was a violent eruption in March 1856. A large portion of the mountain fell down, and tremendous floods of water issued forth. The destruction that ensued was dreadful, upwards of two thousand persons having perished.

In another part of the Indian Ocean, near Madagascar, lies the little Isle of Bourbon, containing the volcano Salazes, which occasionally throws out the curious thready substance already mentioned, so strongly resembling spun glass.



CHAPTER XI.

Mud and Air Volcanoes—Luss—Macaluba—Taman—Korabetoff—New Island in the Sea of Azof—Jokmali—Fires of Baku—Mud Volcano in Flank of Etna—Air Volcanoes of Turbaco, Cartagena, and Galera- Zamba.

The curious mud volcano in the Island of Java, described in the preceding chapter, although presenting some peculiar features, is not the only one of the kind in the world. Mud, as you have learned, is often thrown out in great quantities, along with boiling water, even by true volcanoes, which at other times eject ashes and lava. But there are some volcanoes that never throw out anything else than mud and water, gas and steam. Such are called mud volcanoes or salses.

The most remarkable assemblage of mud volcanoes in the world exists in the district of Luss, lying at the south-east corner of Beloochistan. They extend over a very large area, and are exceedingly numerous. The cone of one of them is no less than four hundred feet high, and the crater at the top is ninety feet in diameter. The mud in the crater is quite liquid, and is constantly disturbed by bubbles of gas, and occasionally by jets of the mud itself.

More familiarly known is the mud volcano of Macaluba, near Girgenti, in Sicily. It is situated in a country much impregnated with sulphur and other inflammable matters. The top of the hill is covered with dry clay, in which are numerous basins full of warmish water mixed with mud and bitumen. From these small craters bubbles of gas arise from time to time; but at long intervals they become much more active, and throw up jets of wet mud to the height of nearly two hundred feet. This mud smells strongly of sulphur.

In the peninsula of Taman, near the entrance to the Sea of Azof, there is a group of mud volcanoes, from one of which there was a considerable eruption on the 27th of February 1793. It was preceded by underground detonations, and accompanied by a column of fire and dense vapour, which rose to the height of several hundred feet. The discharge of mud and gas was abundant. The accompaniment of fire and smoke makes this eruption more nearly resemble that of a true volcano.

There is in the adjacent parts of the Crimea a mountain named Korabetoff, which also presents similar phenomena. On the 6th of August 1853, a column of fire and smoke was seen to rise from the top of this mountain to a great height, and it continued for five or six minutes. Two other similar but less violent ejections of fire and smoke followed at short intervals. These appearances were the accompaniments of an eruption of black fetid mud, which overspread the ground at the foot of the mountain to a considerable depth.

A still more striking phenomenon occurred in the Sea of Azof, on the 10th of May 1814. On that day a column of flame and very thick smoke arose out of the water, with a loud report like that of a cannon, and masses of earth with large stones were tossed high up into the air. Ten eruptions of this kind succeeded each other at intervals of about a quarter of an hour; and after they had ceased for a time, they began again during the night. Next morning it was found that an island had risen out of the sea, between nine and ten feet in height, surrounded by a lower level of hardened mud. A strong fetid smell, probably that of petroleum, proceeded from the island, and extended for a considerable distance all round.



Another mud volcano, named Jokmali, near the Caspian Sea, was formed in November 1827. In this case, also, the ejection of mud was for several hours preceded by flames, rising to so great a height that they could be seen at a distance of twenty-four miles. Large pieces of rock were at the same time thrown up and scattered to considerable distances all round. The entire district in which this mountain is situated, has its soil copiously impregnated with petroleum, and numerous wells are formed for its collection. Quantities of this mineral oil are frequently found floating on the sea, along the neighbouring shores, where the sailors are in the habit of setting fire to this floating petroleum, while they dexterously steer their boats so as to avoid the flames. In this district also stands the city of Baku, held sacred by the Parsees, or fire-worshippers, who have here built a temple, in which are kept burning perpetual fires, fed by the naphtha springing from the ground.

During the past year, 1866, a small mud volcano has been formed in the flanks of Mount Etna. It began with an outburst of strong jets of boiling water. First, one rose to the height of about six feet, then several others broke out, whereupon the height of the whole set diminished. There was much gas bubbling through the water, and some petroleum floated on its surface. It was very muddy, and left a thick deposit as it flowed away. Neither flames nor noise accompanied this eruption.

There are also diminutive volcanoes, consisting of small conical hills, from which nothing seems to be emitted but various sorts of gas. These are called air volcanoes. Such are those of Turbaco in South America, discovered by Baron Humboldt, who has left us a picture of them, of which you here have a copy. These volcanic hillocks are truncated cones, eighteen or twenty in number, composed of hardened mud, from 18 to 24 feet in height, and from about 140 to about 180 feet in diameter at the base. The small craters at the top are filled with liquid mud, whence bubbles of gas, chiefly nitrogen, are being continually disengaged.

There is a similar, but much larger, group in the neighbouring province of Cartagena. It consists of about one hundred cones spread over a district of nearly four hundred square leagues. There is also a group of about fifty cones within a range of four or five miles in the adjacent peninsula of Galera-Zamba. A sub-marine volcano, from which there have been several eruptions, is supposed to be connected with these numerous salses.



CHAPTER XII.

New Zealand—Boiling Fountains and Lakes

In the eruptions of mud volcanoes, described in the foregoing chapter, a frequent ingredient is boiling water. There are, however, several instances in which there are thrown up jets of boiling water that are not intermingled with mud, but in which the water is either pure or impregnated with some mineral which it holds in perfect solution. Of this nature are the Geysers of Iceland and California, already described.

In New Zealand there is another variety of this phenomenon, the boiling water issuing forth, not in intermittent jets, as in the Geysers, but in perpetually flowing springs, forming lakes, in which the water remains nearly at the boiling point. These springs and lakes occur at a place called Roto-Mahana. The annexed woodcut will convey an idea of their appearance.

There are several basins raised one above another, and all higher than the level of the large lake. The highest is of an oval form, and about two hundred and fifty feet in circumference. It is filled from an opening at the height of about a hundred feet above the level of the lower lake. At various stages below this upper basin are numerous other springs, from which several similar basins are filled. The whole of these basins empty themselves into the large lake below, and the water in all of them is nearly boiling hot, giving forth, with a hissing sound, volumes of white vapour.



These waters are richly impregnated with carbonate of lime, which has formed all round the margins of the basins beautiful incrustations of snowy whiteness. The sand round the lake is very warm; and if a stick be thrust into it, jets of steam arise.

Doubtless, some years hence, the enterprising English settlers will establish hot baths here. Not far from the lake there are smaller basins, in which the water is not beyond what would be agreeable for a warm bath; while it is of a blue colour and beautifully clear.

On both banks of the river Waikato, also in this neighbourhood, are found numerous basins full of boiling mud or slime, which cannot be approached save with extreme care, owing to the softness and slipperiness of the soil. The largest of these basins is oval in form, 14 feet long by 8 feet wide, and about as much in depth. It contains hot mud of a bright red colour, being strongly impregnated with oxide of iron. Large viscous bubbles are continually rising to the top, and on bursting they emit a fetid, sulphureous smell. These phenomena are nearly akin to those of a mud volcano.



CHAPTER XIII.

Underground Sounds—Quito—Rio Apure—Guanaxuato—Melida—Nakous.

Not the least remarkable among the phenomena produced by volcanic forces, are the strange underground noises which are occasionally heard. For the most part these are the preludes either of shocks of earthquake or of volcanic eruptions. Those which for months preceded the upheaval of the volcano of Jorullo, will recur to your remembrance. For about a month before the great mud eruption from Tunguragua on 4th February 1797, already described, there proceeded from the interior of that mountain noises of the most fearful kind. These would occur suddenly in the midst of perfect silence. They were heard by Antonio Pineda, the naturalist, who was there at the time, and they led him to foretell the approach of some great convulsion. Strange to say, however, the catastrophe itself was unaccompanied by underground noises any where near the volcano. But, stranger still, at Quito, which is distant about 200 miles, a short time after the eruption began, there were heard tremendous underground thunders. But this distance, between the site of the underground noises and the probable focus of disturbance, was far exceeded in another remarkable instance. It is stated by Humboldt that, in the grassy plains of Calaboso, on the banks of the Rio Apure, a tributary of the Orinoco, there were heard, over a large extent of country, loud underground thunders, unaccompanied by any shaking of the ground; while great streams of lava were being poured forth from the crater of Morne-Garou, in the Island of St. Vincent, at the distance of no less than 632 miles in a right line. This was as though an eruption of Mount Vesuvius were accompanied by underground thunders in Normandy.

There have, nevertheless, been instances of the existence of such underground noises, without their having been followed either by an earthquake, by a volcanic eruption, or any other outward appearance whatever. One of the most remarkable cases of the kind, was that mentioned by Humboldt as having occurred at Guanaxuato in Mexico, a mountain-city situated far from any active volcano. This celebrated traveller states that these noises began on the 9th of January 1784, and lasted above a month. The sounds were at first neither very loud nor very frequent; but from the 15th to the 16th of January they resembled continuous low rolling thunder, alternating with short loud thunder-claps. The sounds then gradually died away and nothing came of them, although they excited great terror among the inhabitants while they lasted. There are mines in the neighbourhood fifteen hundred and ninety-eight English feet in depth, yet neither in them nor at the surface could the least tremor be detected.

A somewhat similar phenomenon occurred in the Island of Melida in the Adriatic, off the coast of Dalmatia, where underground rumblings were heard from March 1822 to September 1824; but in this case the sounds were sometimes accompanied by shocks.

A still more singular phenomenon of this sort occurs on the borders of the Red Sea, at a place called Nakous, where intermittent underground sounds have been heard for an unknown number of centuries. It is situated at about half a mile's distance from the shore, whence a long reach of sand ascends rapidly to a height of about three hundred feet. This reach is about eighty feet wide, and resembles an amphitheatre, being walled in by low rocks. The sounds coming up from the ground at this place recur at intervals of about an hour. They at first resemble a low murmur; but ere long there is heard a loud knocking, somewhat like the strokes of a bell, and which, at the end of about five minutes, becomes so strong as to agitate the sand.

The explanation of this curious phenomenon given by the Arabs, is, that there is a convent under the ground here, and that these sounds are those of the bell, which the monks ring for prayers. So they call it "Nakous," which means a bell. The Arabs affirm that the noise so frightens their camels when they hear it as to render them furious. Philosophers attribute the sounds to suppressed volcanic action—probably to the bubbling of gas or vapours underground.



CHAPTER XIV.

Extinct Volcanoes—Auvergne—Vienne—Agde—Eyfel—Italy—Lacus Cimini—Grotto del Cane—Guevo Upas—Talaga Bodas—The Dead Sea.

There are two sorts of extinct volcanoes: first, those in which all evidences of activity have entirely ceased; and, secondly, those in which a subdued state of activity lingers. The former are more widely distributed than the latter; but sometimes both kinds occur in the same district of country.

Extinct volcanoes are found in the district of Auvergne in France. Solidified streams of lava occur at Volvic near Riom; and the crater whence they descended is still visible on the top of the Puy de Nugere. It is an oblong basin, having its edge broken on the side down which the lava flowed. In its descent the fiery stream appears to have encountered a knoll of granite, by which it was divided into two branches. These seem to have reunited lower down, and thence to have overspread the valley beneath.

The Puy de Come, a mountain near Clermont, appears to have sent forth two streams of lava, which have effected considerable changes in the surface of the country—blocking up the courses of rivers diverting them into new channels, and forming swamps in the old. On the top of Puy Pariou, to the north of Clermont, there exists a perfect crater, quite round, and about two hundred and fifty feet deep, whence there has flowed a stream of lava, whose course can be distinctly traced. The summit of Puy Graveniere, a long round- backed hill also near Clermont, consists almost entirely of a heap of volcanic cinders, which have obliterated all traces of a crater; but two streams of lava appear to have flowed from the sides of the mountain. The Puy de Dome, and the mountains in its neighbourhood, likewise appear to be of volcanic origin, and to have been upheaved somewhat in the same manner as Jorullo. Although the aspect of the mountains of Auvergne indicates so clearly their having been active since the surrounding country acquired its present general conformation, neither history nor tradition has preserved any record of their eruptions.

There is extant, however, a letter from Sidonius Apollinaris, a cotemporary of Pliny, addressed to the Bishop of Vienne, in which he refers to forms of prayer which had been appointed by the bishop at the time when earthquakes demolished the walls of Vienne, and the mountains, opening, vomited forth torrents of inflamed materials. It hence appears that the extinct volcanoes in the neighbourhood of Vienne, and perhaps those of Le Puy, had been in a state of eruption not long after the beginning of the Christian era. To the westward of the latter town, there is a number of small volcanic craters, of which the two largest are the Lake de Bouchet and the Crater of Bar, which also appears to have been at one time a lake, but is now dry. The former has its greatest diameter about 2300 feet, with a depth of about 90 feet. The latter is on the top of a mountain, which is composed entirely of such substances as are ejected by volcanoes. Its diameter is about 1660, and its depth about 130 feet; while it is almost perfect in its form. The mountains near Vienne exhibit streams of lava, which accommodate themselves to the existing valleys. Near Agde also, on the shores of the Gulf of Lions, on the top of a hill named St. Loup, there is an extinct crater, whence have descended two streams of lava apparently of recent origin. On one of them the town of Agde has been built; the other projects into the sea.

The district of Eyfel, on the borders of the Rhine, is another in which extinct volcanoes abound. They occur mostly in the form of circular craters, which are now filled with water, their borders consisting of volcanic ejections. They also exhibit various superficial streams of lava. One of the most remarkable of these round craters lies near Andernuch, a little west of the Rhine. It is named the Lake of Laach, and is nearly two miles in circumference. On its margin are found numerous volcanic ejections, exactly resembling those of Mount Vesuvius. Notwithstanding these evidences that the extinct volcanoes of Eyfel have been in activity since the country acquired its present conformation, there are no historical records of their operations. There is, indeed, a passage in Tacitus referring to fires that issued from the earth near Cologne; but his description does not warrant the conclusion that the event to which he alludes was of the nature of a volcanic eruption. The Drachenfels on the eastern bank of the Rhine, and the other mountains in its neighbourhood, belong to the more ancient volcanic formations. The same may be affirmed of the other mountains scattered throughout Germany and central Europe generally, in which rocks of volcanic origin occur.

There are a good many traces of extinct volcanoes in Italy, besides those of the Phlegraean fields already mentioned. In general character they resemble those previously described. The chief localities are certain lakes, near Volterra in Tuscany, which give forth very hot sulphurous and boracic acid vapours; a small sulphureous lake near Viterbo continually giving forth bubbles of gas; the Lake of Vico between Viterbo and Rome; the mountain and Lake of Albano near Rome; Mount Vultur in the Apennines, in the province of the Basilicata; and Lake Agnano near Naples. Of these, the Lakes of Vico and Agnano are the most interesting. The former is the ancient Lacus Cimini, and old authors state that its site was once occupied by a town, whose ruins used to be visible at the bottom of the lake when the water was clear. The ground, with the town upon it, is said to have been ingulfed during a volcanic convulsion, when the lake was formed in its place.

The Lake Agnano is the site of an ancient volcanic crater, and on its margin is situated the Grotto del Cane, so famous for the deadly vapours it exhales. These consist of carbonic acid gas, in combination with watery vapour. This celebrated Grotto is thus described, in his work on volcanoes, by Dr. Daubeny, who visited the spot:—

"The mouth of the cavern being somewhat more elevated than its interior, a stratum of carbonic acid goes on constantly accumulating at the bottom, but upon rising above the level of its mouth, flows like so much water over the brim. Hence the upper part of the cavern is free from any noxious vapour; but the air of that below is so fully impregnated, that it proves speedily fatal to any animal that is immersed in it, as is shown to all strangers by the experiment with the dog.

"The sensation I experienced, on stooping my head for a moment to the bottom, resembled that of which we are sometimes sensible on drinking a large glass of soda water in a state of brisk effervescence. The cause in both instances is plainly the same.

"The quantity of carbonic acid present in the cavern at various heights, was shown by immersing in it various combustibles in a state of inflammation. I found that phosphorus would continue lighted at about two feet from the bottom, whilst a sulphur match went out a few inches above, and a wax taper at a still higher level.

"It was impossible to fire a pistol at the bottom of the cavern, for although gunpowder may be exploded even in carbonic acid by the application of a heat sufficient to decompose the nitre, and consequently to envelop the mass in an atmosphere of oxygen gas, yet the mere influence of a spark from steel produces too slight an augmentation of temperature for this purpose."

Similar phenomena, but on a grander scale, are presented by the extinct crater in the Island of Java called "Guevo Upas," the Poison-Valley. It is a level about half a mile in circumference, surrounded by precipitous rocks. From various parts of its soil carbonic acid gas is discharged in such quantities as to prove fatal to any animal venturing nigh. The ground is consequently strown with numerous skeletons. This valley gave rise to the famous figment about the upas-tree, which once obtained such general belief in Europe.

There is another extinct crater in Java, whence are exhaled vapours equally deadly, but which exert a most peculiar effect on the dead carcasses subjected to their influence. Instead of their being, as in the Gruevo Upas, reduced to skeletons, the carcasses have all their bones dissolved by the vapours; while the flesh, skin, hair, and nails are by their action preserved from decay. This remarkable crater is situated near the volcano of Talaga Bodas.

Of all the extinct volcanoes in the world, however, none is so remarkable as the Dead Sea. That singular collection of salt and bitter water has the level of its surface depressed 1312 feet below that of the Mediterranean—thus indicating an enormous subsidence. The Dead Sea occupies the site of what was formerly the plain of Jordan, described as having been "well-watered everywhere, as the garden of the Lord, like the land of Egypt." One part of it, called the Vale of Siddim, was full of slime-pits—the only indications of volcanic action. When the cities of Sodom and Gomorrah, which stood in the plain, were destroyed, the Lord, it is said, rained upon them fire and brimstone from heaven; but while these fell upon the cities from the atmosphere, it appears that they must have primarily been discharged from the earth; for "the smoke of the country went up as the smoke of a furnace." The phenomena, therefore, most likely resembled, in the first instance, those of Jorullo; but the catastrophe seems to have ended like the last great eruption of the volcano in Timor—the whole of the plain having been ingulfed and replaced by the salt lake, whose depressed level so clearly indicates the nature of its origin.

THE END