boat had there been any wind; indeed they conceived they had run upon some sand-bank.

About one, a. m. a second, but slight, shock was experienced; but, from the hour, was only noticed by a few.

The mercury in the barometer was much agitated immediately after the earthquake, and a small fire-ball was observed in the air, in a direction from north to south, immediately succeeding it.

SECTION IV.

VOLCANIC ISLANDS, &C.

Volcanic Island lately thrown up among the Aleutian Islands.

16. A new volcanic island has been raised among the Aleutian Islands, not far from Unalaschka. This phenomenon appeared in the midst of a storm, attended with flames and smoke. After the sea was calmed, a boat was sent from Unalaschka, with twenty Russian hunters, who landed on this island, June 1st, 1814.

They found it full of crevices and precipices. The surface was cooled to the depth of a few yards, but below that depth it was still hot. No water was found on any part of it. The vapours rising from it were not injurious, and the sea-lions had began to take up their residence on it. Another visit was paid to it in 1815; its height was then diminished. It is about two miles in length; they have given it the name of Boguslaw.

Geological Account of the Island of Jan Mayor.

17. This remote and desolate spot, situated in lat. 70° 49′ N. and long. 7° 25′ W. was visited by Capt. Scoresby in Aug. 1817. On approaching, the first object which strikes the attention is the mountain of Beerenberg, which rears its icy summit to the height of 6840 feet above the level of the

sea.

All the high lands were covered with snow; and the low lands in deep cavities still retained part of their winter covering down to the very margin of the sea. Captain S. observed three remarkable ice bergs, having a perpendicular height of 1284 feet.

The beach was covered with a sand having the appearance of coarse gun-powder: being a mixture of iron, sand, olivine, and augite. As he advanced towards the rocks, he found masses of lava, blocks of burned clay, and masses of baked clay. He ascended to the summit of a volcanic mountain 1500 feet above the sea, where he beheld a crater forming a basin of 500 or 600 feet deep. From this eminence, the country in all directions appeared bleak and rugged in the extreme-all indicated the action of volcanic fire; the plants were few in number; the animals were blue foxes. He also saw the feet-marks of bears, and he thinks reindeer; but few birds were seen.

Geological Structure of St. Vincent's, one of the West India Islands.

18. St. Vincent's, like all other volcanic islands, is composed of a mixture of lava and cinders, in all proportions. South of Kingston, there appears to be more solid and porous lava, and less cinders than at the north. The Bay of Kingston has the appearance of being the remains of an ancient crater, the beds of lava inclining irregularly from the centre, at a considerable dip, as if they had been ejected from it. On every side, the rocks are aggregates of various kinds of roasted stones, cemented with cinders, and small atoms of scoria; and though many of the rolled rocks neither bear strong marks of fusion, nor resemble much recent lavas, yet they all have a family feature, and must be considered of volcanic origin. A substance like horn-. blend, with feldspar imbedded in it, forms the principal part of these rocks, which vary in colour, from nearly black to grey, the feldspar being generally

crystallized, and frequently diaphanous, passing through the porous or scorious rocks without indications of having undergone much change.

There are two principal modes by which the production of cinders or ashes may be accounted for; they may be thrown from the crater of a volcano during an eruption of lava, and in that case they consist of small pieces of scoria, pumice, &c. and are placed in strata of various thicknesses and colours, as if deposited by water; or they may be ejected from volcanoes nearly exhausted mixed with water and rocks, forming large beds or currents of an aggregate, which is in time cemented, and wears the appearance of a breccia. A third mode is, perhaps. the eruption of lava into the sea, at the commencement of submarine volcanoes, when by means of the sudden cooling, the melted lava might crumble into small angular sand, and form beds of cinders. From Kingston to the north end of the island, the same alternation of cinders and solid lava obtains, forming steep precipices and narrow vallies, the wearing and excavation of which, by the mountain torrents, is facilitated by the prevalence of the cinders which increase as you approach the Soufriere, a name given in the West Indies, to spots which indicate the remains of a subsiding volcano, and whence hot sulphueous vapours are ejected through fumerols, depositing sulphur, and converting the surrounding aluminous rocks into alum-stone, as at Solfaterra near Naples.

The fumerols of this Soufriere are at present extinguished, perhaps by the last irruption of cinders in 1812, when the orater threw forth a mixture of water, rocks, and cinders in a state approaching to ignition, resembling a current of lava; burning the woods, and filling all the channels of the little rivers that descend the mountain, and rising sometimes to the height of three or four hundred feet. Very fine cinders fell on the decks of vessels three or four hundred miles to windward, supposed to have been carried by a counter current of air, in the upper regions of the atmosphere.

This irruption consisted of a great quantity of angular sand, the broken masses of roasted and vitrified rocks being mixed with loose angular pieces of all sizes, brittle, and crumbling under the ham

mer

These imbedded rocks are, 1st. A rock resembling a small and middling sized grained granite, roasted, with diaphanous feldspar. 2nd, A gray rock, in plates, like gneiss, but much

altered by the fire. 3d, A feldspar and hornblend rock, the feldspar crystallized and diaphanous, with the appearance of having been roasted. 4th, A hornblend rock, crystalline, having a roasted appearance. 5th, A dark coloured rock, with a conchoidal, even, vitreous fracture, containing crystals of feldspar, some pieces so vitreous as to resemble pitchstone, and porphyry running through all the gradations from a grey rock, scarcely vitrified, to a total vitrification, and thence to a porous scoria, not unlike pumice, with transparent crystals of feldspar, taking a deeper tinge of black in proportion to the degree of vitrification. 6th. A bluish rock with feldspar, and some black crystals, having all the appearance of compact lava.

If we suppose that volcanic action tends to form large cavities under the places whence the lava, &c. issues, and that one, or more, of these cavities, where the combustible materials are exhausted, becomes filled with water, while other cavities, where these materials still remain, are filled with lava, &c. it would appear only necessary to unite the contents of two such caverns to produce all the effects of an irruption of cinders.

Island of Ischia, near Naples.

19. To the most superficial observer, the surface of this island exhibits the effects of fire, and volcanic productions; besides many craters, long extinct; and strata of lava, in different stages of vegetation. The lava of the most recent eruption, in 1301, even now bears only a few scattered blades of grass, and some weeds. Hence we may judge how slowly nature operates on this hard substance, when not assisted by the soil washed down from the declivities of mountains, or wafted by the wind. If we examine the many craters with which this spot abounds, particularly the large crater between Ischia and Testaccio, close to the side of the road; if we next turn our view to the adjoining mountains, at present covered with a deep soil, and clothed

with wood, we may calculate the high antiquity, not only of such eruptions, but of the globe itself.

Indeed, amidst the various evidences which have been adduced by those authors who have chosen to controvert the general opinion on the supposed age of the world, none seem to carry more force than those deduced from the investigation of volcanic matter. Nor are these evidences founded on mere conjecture; for the dates of many eruptions are known; and, by tracing the strata of lava, and the marine bodies interspersed, and comparing the relative progress of vegetation over each, we may draw a very probable conclusion in regard to the age of the more remote; and, perhaps, may be induced to give the world a higher degree of antiquity than is commonly admitted.

For nearly five centuries this island has ceased to exhibit any volcanic eruption; but the numerous hot springs, which continue to emit their vapour, prove that subterraneous fire still exists. Besides these warm springs, however, there are others of an opposite nature; and from the same mountain which produces the sulphureous and medical waters, a cold spring issues, of the purest quality, and is conveyed by aqueducts to the town of Ischia.

The lofty mountain now bearing the name of St. Nicolo, is the Epopeus of the classic writers.

Like Etna, it may be divided into three regions; the lower cultivated, the middle clothed with rich groves of oaks and chesnuts, and the upper bleak aud barren, producing only a few low shrubs and dwarf trees.

It is not, however, without inhabitants; for, on this aërial summit, some hermits have fixed their abode; and no anchorite certainly ever selected a more appropriate spot. Exalted above the dwellings, as they profess to be above the passions of men, they may look down with an eye of indifference on a prodigious expanse of territory, thickly dotted with towns and villages; and, contrast their homely fare and tranquil situation with the cares and troubles which attend the wealth and luxury of the world beneath.