The volcanoes hitherto noticed have generally been arranged in a line with the great chain of the The Icelandic group comprehends the two Andes. The Mexican volcanoes, which come next islands of Iceland and Jan Meyen. On the former under notice, occupy a transverse position-and are reckoned six volcanoes, one of which, Kraabla, stretch from the Atlantic to the Pacific Ocean, at is in constant activity, and on the latter, one. The an average distance of about sixteen miles south third group has already been fully noticed.

of the city of Mexico. According to Humboldt It remains to notice the volcanoes of the souththere are only five active volcanoes in Mexico-ern Atlantic ocean and those in the West India Tustla, Orizaba, Popocatapetl, Jorullo, and Colima. islands. The Azores, Canaries and Cape Verde Later authorities add to these Iztaccihuatl and To- islands, situated almost on the same parallel of luca. The peak of Orizaba is constantly in a state longitude, contain active volcanoes. Among the of ignition, and from its appearance, when seen at West Indian islands active volcanoes occur on St. a distance, it has obtained from the Indians the Vincent, Guadaloupe, and St. Christopher, besides name of the "Mountain Star." some active ones on some of the other islands.

17,000+... Three

15,000+... Two 14,000+... One

Respecting the average frequency of volcanic eruptions on the globe, it may be stated that, according to Sir Charles Lyell, about fifty eruptions occurred during the last century within the five European volcanic districts of Vesuvius, Etna, Lipari Isles, Santorin, and Iceland. Computing these to be about one fourth of the volcanic groups of the globe, which latter are considered to have about an equal activity, he reckons that about two thousand volcanic eruptions occur on the globe in the course of a century; or about twenty every

These are Mt. Elias, on the north-
west coast of North America,
about which being an active vol-year.
cano some doubt exists; and the
two Mexican volcanoes of Popo-
catapetl and Orizaba.
Iztaccíhuatl and Toluca, both Mex-
ican volcanoes.

Buen Tempo, situated between Mt.
Elias and Mt. Edgcumhe.
13,000. Two... The two peaks of Mt. Amilpas.
4,000+. One
...Jorullo.
One of these belongs to the Aleu-
3,000+... Two
tian Islands; the other is Mount
Edgcumbe.

1,000+... One ... In the Aleutian Islands.

CENTRAL AMERICA AND THE ADJACENT ISLANDS-
TEN.

18,000+ One ...Zolima.

15,000

12,000+

11,000

...

...

One Agua.

One

...

Atitlan.

One Trasu, or Volcano de Cartago.
Two... In Guatemala.

9,000+
5,000+ Two... In St. Vincent, and Gaudaloupe.
3,000+ One Mt. Misery, in St. Christopher's.
,000+
Izalco.*

22,000

20,000

£9,000+...

One

...

...

SOUTH AMERICA-ELEVEN.

Two... Somarape and Sehama.
One ... Arequipa.

One... Antisana.

18,000- One Cotopaxi.

...

...

17,000+... One .. Chipicani.

...

The reader having learned from what precedes the general distribution of the volcanoes of the world, and the heights which the most remarkable of them attain, and having gained a general idea of the phenomena exhibited during eruptions, will be interested in the following outlines of narratives of the ascent of two among the highest volcanic mountains in the world-Popocatapt in Mexico, and Mauna Loa in Hawaii, (one of the Sandwich islands.) It will thus appear in what state these mountains are generally found.

Popocatapetl, or the smoke-mountain, is the highest volcanic mountain of the Mexican group. Its elevation exceeds 17,000 feet. It is situated about fifty miles to the east-south-east of the city of Mexico. It is in the shape of a truncated cone. It is situated on the edge of the elevated plateau on which the city of Mexico stands. On one side, therefore, it rises almost from the level of the sea, and on the other from an already high plateau. The appearances of the two sides of the mountain correspond to their difference of position. The whole of the north-west side is clothed below the snow-line with forests of firs, which mingle at the foot with corn, maize and the other European plants which are cultivated at that elevation. On the opposite side, also, occurs a zone of forest trees; but below it other zones occur, which change at almost every step you descend, till in the valley itself, the region of the cactus, the sugar-cane, and the palm would be reached. The snow-line is lower on the northern than on the southern side.

In October, 1519, Cortez and his army passed by Mount Erebus and Sesarga, (in Popocatapetl; they were then on their way to be

the Salomon Isles.)

In Hawaii.

454... One ... Tanna, in the New Hebrides.

Omitting the irregularly active volcanic centre of Santorin and the volcano of Epomeo, which has only once broken out within record, we may consider the active volcanoes of Europe to be three. The volcanoes of the world amount, as before stated, to 270. Comparing the heights of Vesuvius and Etna (Stromboli is lower than either) with the other heights just given, we find that out of sixty-three elevations, there are thirty-two which exceed Etna, and fifty-two surpassing Vesuvius. The mean height of Vesuvius and Etna is 7,411 feet. The mean height of the sixty-one others is 10,677 feet. Mounts Somarape and Sehama are more than twice the height of Mount Etna, and more than five times that of Vesuvius.

The great difference between the height given by Mr. Johnston to this mountain and that given by Mr. Stephens, may probably be accounted for by the heights having been taken at different times. We may here remark, however, that authorities seldom quite agree regarding the height of mountains.

siege the capital of Mexico. Attracted by the novelty of a huge mountain discharging smoke, he sent ten of his most courageous soldiers to "find out the secret. They did not succeed, however, in reaching the summit, owing to the snow and the discharge of cinders. Subsequently, in 1522, after the capture of the city, the Spaniards succeeded in reaching the crater; and, either from this or some other volcanic mountain, sulphur was procured for the manufacture of gunpowder. Cortez, in one of his letters to his sovereign, states this to have been effected by letting a man tied to a cord down into the crater. Humboldt, who records these facts, further relates that a certain Dominican, Blasde Iñena, armed with an iron spoon and pail, caused himself to be let down in an osier basket into the crater of the Cerro de Massaya, in Granada, for the purpose of gathering gold. To what extent he would have enriched himself, we are left to infer, his pail having unfortunately been melted by the heat. What became of the spoon we are not informed; the osier basket reached the top with difficulty, bringing a poorer, but perhaps wiser, man. The dean of the chapter of the town of Leon obtained formal permission from the court of Madrid "to open the same volcano, and to gather

the gold which it contained." It does not appear, I this abyss are emitted, whirling round with the force however, what success attended his operations. of a whirlwind, masses of white exhalations, which It was from the southern side that, in the year disperse when they attain half the height of the 1834, Baron Gros, secretary to the French legation inside of the crater. Some apertures in the declivity at Mexico, M. de Gerolt, Consul-general for Prus- of the funnel project these also, as do likewise seven sia, and Mr. Egerton, an English artist, com- large fissures which are between the strata forming menced their arduous duty of ascending Popocat-rise higher than fifteen or twenty feet. the edge of the crater; but these last vapors do not apetl. The expedition started, says Baron Gros, at bottom are circular and surrounded by a large The apertures at seven o'clock in the morning :zone of pure sulphur. * **The disengagement of the sulphurous gas is so considerable that we were greatly incommoded by it at the top of the volcano. The outward edge of the crater is entirely devoid of snow, but in the inside where the sun has no power, a considerable number of stalactites of ice are found hanging down to where the third stratum begins. The summit of the volcano is a small platform of fifteen or twenty feet in diameter, where the same violet-colored sand is found, which is in such abundance at the base of the cone, and the heat of which is sensible to the touch.

At three, we had arrived at the limits of vegetation, which we reached by almost beaten tracks, having had occasion to use our axes in one place only. To any one acquainted with the Alps, I need not say one word of those stupendous forests of oak, or fir, and of larch, which must be traversed; they are alike in both hemispheres, save at the foot of this mountain are to be found numerous flocks of guacamaias, large green parrots with green heads. There are also in the forests a small species of lion, jaguars, wolves, stags. roes, and a great quantity of wild cats; but we did not see a single one of all these animals. In proportion as we ascended into the wood, the firs became less frequent and of smaller size. Near the sands they are all more or less stunted; and all their branches bend down to earth as if they sought lower down air less rarefied. *** From the moment the wood is left behind, nothing is to be seen up to the third part of the volcanic cone, but an immense extent of violetcolored sand, so fine in some places that the wind ruffles the surface of it with the perfect regularity of a ripple on the waters. Blocks of red porphyry are scattered up and down, and break the monotony of the spectacle. The top of the undulations formed by the sand is covered over by an immense quantity of little yellowish pumice-stones, which the winds appear to have gathered there in heaps; and along these sands run in furrows, till they are lost in the forest, some scoriæ of volcanic rocks descending from the masses of porphyry and black lava which form the top of the mountain. The most elevated part of the volcano is entirely covered with snow, and this snow seems the more purely white that the horizon along which it lies is of a blue so deep as almost to be black.

The baron and his party passed the night on the borders of the forest, setting off again at three o'clock on the following morning. The usual sensations experienced by persons who ascend to great elevations are recorded by Baron Gros. He also adds: "It was necessary to cry very loud in order to be heard at a distance of twenty paces. Indeed, the air at that height was so rarefied, that I tried in vain to whistle, and Mr. Egerton had the greatest difficulty in extracting any sounds from a horn he had brought with him." At three o'clock, the baron and his two companions had reached the summit of the volcano, which proved to be the brink of the crater :

* **

of the Sandwich Islands; it is of an irregular The island of Hawaii, or Owyhee, is the largest shape, being about one hundred miles long from north to south, and eighty miles wide in the broadest part. The interior of the island consists of a tableland 8000 feet above the level of the sea, on the edges of which are situated the three volcanic mountains of Mauna Kea on the east, Mauna Loa at the south-western corner, and Mauna Hualalai on the western side, the two last being still active.

The ever active volcanic crater of Kilanea occupies a shoulder, or terrace, on the eastern slope of Mauna Loa. Mauna Loa was ascended, in December, 1840, by a party belonging to the United narrative of that expedition that the following noStates Exploring Expedition, and it is from the tice is taken. The height of this mountain is given by them as 13,760 feet. After considerable labor the platform on which Kilanea is situated, at a height of about 4000 feet above the sea, was attained. At this point Mauna Loa rose up in all its proportions.

The whole dome appeared of a bronze color, and its uninterrupted smooth outline was relieved against the deep blue of a tropical sky. Masses of clouds were floating around it, throwing their shadows distinctly on its sides, to which they gave occasional relief and variety. There was a bluish haze resting on the plain, that apparently gave it great distance, though this was partially counteracted by the distinctiveness of the dome.

The party now approached the crater of Kilanea.

Vapor issuing from numerous cracks showed that we were passing over ground beneath which fire was raging. The rushing of the wind past us was as if it The crater (says Baron Gros) is an immense gulf, were drawn inwards to support the combustion of almost circular, having a deep depression on the north some mighty conflagration. When the edge is reached, side, and some spiracles on the south. It might be the extent of the cavity becomes apparent, and its about a league in circumference, and nine hundred or depth became sensible by comparison with the figures a thousand feet in perpendicular depth. The walls of of some of our party who had already descended. The the gulf were peaked. They distinctly present three vastness thus made sensible transfixes the mind with large horizontal strata, intersected perpendicularly astonishment, and every instant the impression of and almost at equal distances by black and grayish grandeur and magnitude increases. To give an idea lines. The bottom is a funnel, formed by successive of its capacity, the city of New York might be placed convulsions, still occurring almost daily. The inside within it, and when at its bottom would be hardly edge, from the surface to about fifteen or twenty feet noticed; for it is three and a half miles long, two and lower, is a mass of red, black, or whitish, very thin a half wide, and over a thousand feet deep. A black strata, upon which rest the blocks of volcanic rocks ledge surrounds it at the depth of 660 feet, and thence yet destined to fall into the crater. Its walls are to the bottom is 384 feet. The bottom looks, in the yellowish, and present at first glance the appearance day time, like a heap of smouldering ruins. The of a limestone quarry. The bottom and the inclined descent to the ledge appears to the sight a short and plane of the funnel are covered with an immense easy task, but it takes an hour to accomplish. *** quantity of blocks of sulphur, perfectly pure. From All usual ideas of volcanic craters are dissipated upon

seeing this. There is no elevated cone, no igneous succeeded in reaching the floor of the crater by this matter, or rocks ejected beyond the rim. The banks ap-means. pear as if built of massive blocks, which are in places | clothed with ferns, nourished by the issuing vapors. What is wonderful in the day becomes ten times more so by night. The immense pool of cherry-red liquid lava, in a state of violent ebullition, illuminates the whole expanse, and flows in all directions like water, while an illuminated cloud hangs over it like a vast canopy.

The crater contains two lakes of liquid lava, the larger of which is estimated at 1500 feet long, and 1000 wide. At a height of 500 feet above the larger lake the light was so strong that the smallest print could be read.

I was struck (says the narrator) with the absence of any noise, except a low murmuring, like that which is heard from the boiling of a thick liquid. The ebullition was (as is the case where the heat is applied to one side of a vessel) most violent near the northern side. The vapor and steam that were constantly escaping were so rarefied as not to impede the view, and only became visible in the bright cloud above us, which seemed to sink and rise alternately. We occasionally perceived stones, or masses of red-hot matter, ejected to the height of about seventy feet, and falling back into the lake again. The lake was apparently rising, and wanted but a few feet of overflowing its banks. The immense space which I have described the crater as covering, is gradually filled with the fluid mass of lava to a certain point, above which the walls, or the surrounding soil, are no longer able to bear the pressure; it then finds vent by an eruption, previous to which, however, a large part that is next to the walls of the crater has, in a measure, become cooled, and remains fixed at the level it has attained. After the eruption, the central mass therefore alone subsides three or four hundred feet, and leaves the portion that has become solid forming a kind of terrace or shelf; this is what constitutes the "black ledge," and is one of the most striking features of the crater. Its surface is comparatively level, though somewhat uneven, and is generally coated with a vitreous, and in some places a scoriaceous lava, from half an inch to an inch thick, very brittle. ling noise made in walking over this crisp surface (like a coating of blue and yellow glass) resembles that made by treading on frozen snow in very cold weather. Here and there are seen dark pits and vaulted caverns with heated air rushing from them. Large and extended cracks are passed over, the air issuing from which, at a temperature of 180°, is almost stifling. Masses are surmounted that it would seem as if the accumulated weight of a few persons would cause to topple over, and plunge into the fiery pool beneath. From many places on the black ledge a bluish smoke was seen issuing, smelling strongly of sulphur, and marked by an efflorescence of a white tasteless powder among the cavities; this it was difficult to detach without scalding the fingers. There were many cracks where our sticks were set on fire, and some places in the vaulted chambers beneath where the rock might be seen red-hot. The black Tedge is of various widths, from 600 to 2000 feet. It extends all around the cavity, but it is seldom possible to pass around that portion of it near the burning lake, not only on account of the stifling fumes, but of the intense heat. In returning from the neighborhood of the lake to the point where we began the ascent, we were one hour and ten minutes of what we considered hard walking, and in another hour we reached the top of the bank.

* *

*

*

Like the black ledge, it was not found to have the level and even surface it had appeared from above to possess; hillocks and ridges, from twenty to thirty feet high, ran across it, and were in some places so perpendicular as to render it difficult to pass over them. The distance they traversed below was deceptive, and they had no means of ascertaining it but by the time it took to walk it, which was upwards of two hours from the north extreme of the bottom to the margin of the large lake. It is extremely difficult to reach this lake on account of its overflowing at short intervals, which does not afford the fluid mass time to cool. The nearest approach that any one of the party made to it at this time was about fifteen hundred or two thousand feet; they were then near enough to burn their shoes and light their sticks in the lava, which had overflowed during the preceding night. The smaller lake was well viewed from a slight eminence. This lake was slightly in action; the globules (if large masses of red fluid lava, several tons in weight, can be so called) were seen heaving up at regular intervals six or eight feet in height; and smaller ones were thrown up to a much greater elevation. At the distance of fifty feet no gases were to be seen, nor was any steam evident; yet a thin smoke, like vapor, arose from the whole fluid surface: no puffs of smoke were perceived at any time.

From time to time the surface of the heated fluid would crack and exhibit a bright red glare. From these cracks streams of lava issued, so as gradually to extend the boundaries of the lake, and to drive the observers from their position.

The exploring party, having satisfied their curiosity at the volcano of Kilanea, proceeded to complete the task of ascending Mauna Loa. This was not accomplished without difficulty.

Nothing (says the narrative) can exceed the devastation of the mountain; the whole area of it is one mass of lava, that has at one time been thrown out in a fluid state from its terminal crater. There is no sand or other rock; nothing but lava, on whichever The crack-side the eye is turned. To appearance it is of different ages; some of very ancient date, though as yet not decomposed; and the alternations of heat and cold, with rain and snow, seem to have united in vain for its destruction.

At the north-west angle of the black ledge there was a descent to the bottom of the crater, where a

portion of the ledge had fallen in and afforded an inclined plane to the bottom. Two of the party

A fall of snow took place before the summit was reached. The thermometer at the summit stood at 15°. The view from the summit is thus described :

In the distance, [towards the north,] the island of Mani emerged from and broke the line of the deep blue horizon, while its lower side was dimmed by a whitish haze, that seemed to unite it to the island of Hawaii. The same haze enveloped the hills of Kohala on our right, and the western extremity of Hawaii. Nearer to us was Hualalai, up whose sides a compact mass of white fleecy clouds was impelled by the sea-breeze. To our right, rose in bold relief Mauna Kea, covered with its snowy mantle; and at our feet was spread out, between the three great mountains, the black plain of lava, overhung by a dusky pall of clouds. All these features were so blended into each other by the mist, as to exhibit a tone of harmony that could hardly be conceived, considering the variety of the forms, characters, and distances of the objects, and which seemed to blend earth, sea, and sky into one.

The terminal crater is thus described :

This crater, or rather craters-for there are two

separated by a narrow partition of compact lava and clinkers-is an immense depression, with an elevated

Erim about twenty miles in circumference, which | for a long period, without any earthquake occur gradually narrows by successive ledges to the depth ring. When the earthquake originates in the sea, of eight or nine hundred feet. It has been dormant and is thence propagated to the land, the sounds, for many years, but is still filled with fissures and caverns, which emit steam and sulphureous vapors.