the midft of the fea, which, though for a long time barren, have afterwards become fruitful feats of happiness and industry.

Ancient hiftorians, and modern travellers, give us fuch accounts as we can have no room to doubt of. Seneca affures us, that in his time the island of Therafia appeared unexpectedly to fome mariners, as they were employed in another purfuit. Pliny affures us, that thirteen iflands in the Mediterranean appeared at once emerging from the water; the caufe of which he afcribes rather to the retiring of the fea in thofe parts, than to any fubterraneous elevation. However, he mentions the island of Hiera, near that of Therafia, as formed by fubterraneous explosions; and adds to his lift several others, formed in the fame manner. In one of which he relates that fish in great abundance were found, and that all thofe who ate of them died fhortly after.

"On the twenty-fourth of May, in the year 1707, a flight earthquake was perceived at Santorini; and the day following, at fun-rifing, an object was feen by the inhabitants of that ifland, at two or three miles diftance at fea, which appeared like a floating rock. Some perfons, defirous either of gain, or excited by curiofity, went there, and found, even while they ftood upon this rock, that it feemed to rife beneath their feet. They perceived also that its furface was covered with pumice ftones and oyfters, which it had raised from the bottom. Every day after, until the fourteenth of June, this rock feemed confiderably to increase; and then was found to be half a mile round, and about thirty feet above the sea. The earth of which it was compofed feemed whitish, with a

fmall

fmall portion of clay. Soon after this the fea again appeared troubled, and steams arofe, which were very offenfive to the inhabitants of Santorini. But on the fixteenth of the fucceeding month, feventeen or eighteen rocks more were seen to rife out of the fea, and at length to join together. All this was accompanied with the most terrible noife, and fires which proceeded from the island that was newly formed. The whole mafs, however, of all this new-formed earth, uniting, encreased every day, both in height and breadth, and by the force of its explosions, caft forth rocks to seven miles diftance. This continued to bear the fame dreadful appearances till the month of November in the fame year; and it is at prefent a volcano which fometimes renews its explosions. It is about three miles in circumference; and more than from thirty-five to forty feet high."

It seems extraordinary, that about this place in particular, iflands have appeared at different times, particularly that of Hiara, mentioned above, which has received confiderable additions in fucceeding ages. Juftin tells us, that at the time the Macedonians were at war with the Romans, a new ifland appeared between thofe of Theramenes and Therafia, by means of an earthquake. We are told, that this became half as big again about a thousand years after; another island rising up by its fide, and joining to it, fo as fcarce at prefent to be distinguished from the former.

A new ifland was formed, in the year 1720, near that of Tercera, near the continent of Africa, by the fame caufes. In the beginning of December, at night, there was a terrible PART. II. E

earth

earthquake at that place, and the top of a new island appeared, which caft forth smoke in vast quantities. The pilot of a ship, who approached it, founded on one fide of this ifland, and could not find ground at fixty fathom. At the other fide the fea was totally tinged of a different colour, exhibiting a mixture of white, blue, and green; and was very fhallow. This island, on its first appearance, was larger than it is at present; for it has, fince that time, funk in fuch a manner, as to be fcarce above water.

A traveller, whom these appearances could not avoid affecting, fpeaks of them in this manner: "What can be more furprifing than to fee fire not only break out of the bowels of the earth, but also to make itself a paffage through the waters of the fea! What can be more extraordinary or foreign to our common notions of things, than to fee the bottom of the fea rife up into a mountain above the water, and become fo firm an ifland as to be able to refift the violence of the greatest ftorms! I know that fubterraneous fires, when pent in a marrow paffage, are able to raise up a mass of earth as large as an island. But that this should be done in fo regular and exact a manner, that the water of the fea fhould not be able to penetrate and extinguish thofe fires; that, after having made fo many paffages, they fhould retain force enough to raise the earth; and, in fine, after having been extinguished, that the mafs of earth fhould not fall down, or fink again with its own weight, but ftill remain in a manner fufpended over the great arch below! This is what to me feems more surprising

than any thing that has been related of Mount Etna, Vefuvius, or any other volcano."

Sir WM. HAMILTON, in his researches among the volcanic iflands around Sicily, is of opinion, that they also owe their origin to fubterraneous fires; and indeed he thinks, that though volcanos may deftroy what is more immediately within their reach, yet, on the whole, they are beneficial and

creative.

Such is the effect of fires which proceed from the more inward receffes of the earth. Mr. Buffon, indeed, fuppofes them rooted but very little below the beds of mountains. But the contrary feems demonftrated by a well-known fact; namely, that the quantity of matter difcharged from Ætna alone, is computed to exceed twenty times the bulk of the mountain. The greatest part of Sicily feems covered with its lava. The inhabitants of Catanea have found, at the diftance of feveral miles, ftreets and houses, fixty feet deep, overwhelmed by lava; the walls of thefe very houfes being built of materials evidently thrown up by the mountain. The inference is obvious; this matter thus exploded cannot belong to the mountain itself, it would have been quickly confumed ; it cannot be derived from a moderate depth, fince its amazing quantity evinces, that all around the bottom must have long fnce been exhausted.

By way of contraft to what we have been relating, I wish to remind my auditory, that mountains are alfo the feats of eternal fnow and relentless froft: by a ftrange combination, their internal parts are the refidences of flames and fire; their external

external and fuperior parts are cold as the frozen zone. For as volcanic eruptions are only at intervals, these mountains, in common with others, are fubjected to atmospheric viciffi tudes, and covered with the burdens of the clouds.

The moft interefling fpectacles of this kind, are thofe val leys of fnow fituated among the mountains of Switzerland, with which being beft acquainted we are most impreffed. Every mountain around is fnow, from where we ftand, to those by distance tinged a folid blue, rearing their dreary fummits to the clouds; the valleys beneath and between them, are one vaft bed of ice and fnow, broken into a thousand fantaftic forms. Here, feeming fmooth fheets of glittering white; there, rifing into waves of fnow; interfected here by channels of tremendous depth, narrow and steep; there, feparated by wider breaches. Let none presume that he has but to go strait to his propofed object, ever and anon, will he find new impediments. The frozen ridges will be too perpendicular to climb, or the (apparently) fmall cracks and fiffures will be far too wide to be paffed in fafety; he must go round, on one fide, on the other, and think himself lucky, if in advancing one mile, he walk only four.-Such are the GLACIERES.

The inhabitants of the valleys around thefe Glacieres, pafs their crevices by means of a long pole tied to another, which is held by a companion; this they lay crofs the opening; if the fnow on each bank is firm, the first adventurer gets fafely over, and affists his friend; if it gives way, he would inevitably fall eighty or an hundred fathoms deep, were he not pre