the centre of this circle, the great crater of the mountain rears its burning head; and the regions of intense cold, and of intense heat, seem forever to be united in the same point. On the north side of the snowy region, they assure us there are several small lakes that are never thawed; and that, in many places, the snow, mixed with the ashes and salts of the mountain, is accumulated to a vast depth. And indeed I suppose the quantity of salts contained in this mountain, is one great reason of the preservation of its snows.

The Regione Deserta is immediately succeeded by the Sylvosa, or the woody region, which forms a circle or girdle of the most beautiful green, which surrounds the mountain on all sides, and is certainly one of the most delightful spots on earth. This presents a remarkable contrast with the desert region. It is not smooth and even like the greatest part of the latter; but it is finely variegated by an infinite number of those beautiful little mountains that have been formed by the different eruptions of Etua. All these have now acquired a wonderful degree of fertility, except a very few that are but newly formed; that is, within these five or six hundred years: for it certainly requires some thousands to bring them to their greatest degree of perfection. We looked down into the craters of these, and attempted, but in vain, to number them.

The circumference of this zone or great circle on Ætna, is not less than seventy or eighty miles. It is every where succeeded by the vineyards, orchards, and corn-fields, that compose the Regione Culta, or the fertile region. This last zone is much broader than the others, and extends on all sides to the foot of the mountain. Its whole circumference, according to Recupero, is 183 miles. It is likewise covered with a number of little conical and spherical mountains, and exhibits a wonderful variety of forms and colours, and makes a delightful contrast with the other two regions. It is bounded by the sea to the south and south-east, and on all its other sides by the rivers

Semetus and Alcantara, which run almost round it. The whole course of these rivers is seen at once, and all their beautiful windings through these fertile valleys, looked upon as the favourite possession of Ceres herself, and the very scene of the rape of her daughter Proserpine.

Cast your eyes a little farther, and you embrace the whole island, and see all its cities, rivers and mountains, delineated in the great chart of nature: all the adjacent islands, the whole coast of Italy, as far as your eye can reach ; for it is no where bounded, but every where lost in the space. On the sun's first rising, the shadow of the mountain extends across the whole island, and makes a lare track, visible even in the sea and in the air. By degrees this is shortened, and in a little time is confined only to the neighbourhood of Etna.

We now had time to examine a fourth region of this wonderful mountain, very different indeed from the others, and productive of very different sensa tions; but which has, undoubtedly, given being to all the rest; I mean the region of fire.

The present crater of this immense volcano is a circle of about three miles and a half in circumference. It goes shelving down on each side, and forms a regular hollow like a vast amphitheatre. From many places of this space, issue volumes of sulphureons smoke, which being much heavier than the circumambient air, instead of rising in it, as smoke generally does, immediately on its getting out of the erater, rolls down the side of the mountain like a torrent, till coming to that part of the atmosphere of the same specific gravity with itself, it shoots off horizontally, and forms a large track in the air, according to the direction of the wind; which, happily for us, carried it exactly to the side opposite to that where we were placed.

The crater is so hot, that it is very dangerous, if not impossible, to go down into it; besides the smoke is very incommodious, and, in many places, the sur

face is so soft, there have been instances of people sinking down in it, and paying for their temerity with their lives. Near the centre of the crater is the great mouth of the volcano: that tremendous gulph so celebrated in all ages, looked upon as the terror and Scourge both of this and another life; and equally useful to ancient poets, or to modern divines, when the Muse or when the Spirit inspires. We beheld it with awe and with horror, and were not surprised that it had been considered as the place of the damned. When we reflect on the immensity of its depth, the vast cells and caverns whence so many lavas have issued; the force of its internal fire, to raise up those lavas to so vast a height, to support them, as it were, in the air, and even to force them over the very summit of the crater, with all their dreadful accompaniments; the boiling of the matter, the shaking of the mountain, the explosions of flaming rocks, &c. we must allow, that the most enthusiastic imagi. nation, in the midst of all its terrors, hardly ever formed an idea of a hell more dreadful.

It was with a mixture both of pleasure and pain, that we quitted this awful scene. But the wind had arisen very high, and clouds began to gather round the mountain. In a short time they formed like another heaven belows us, and we were in hopes of seeing a thunder-storm under our feet; a seene that is not uncommon in these exalted regions, and which I have already seen on the top of the high Alps. But the clouds were soon dispelled again by the force of the wind, and we were disappointed in our expectations.

I had often been told of the great effect produced by discharging a gun on the top of high mountains. I tried it here, when we were a good deal surprised to find, that, instead of increasing the sound, it was almost reduced to nothing. The report was not equal to that of a pocket-pistol. We compared it to the stroke of a stick on a door; and surely it is consistent with reason, that the thinner the air is, the less its impression must be on the ear; for in a vacuum

VOL. I.

R

there can be no noise; and the nearer the approach to a vacuum, the impression must always be the smaller. Where those great effects have been produced, it must have been amongst a number of mountains, where the sound is reverberated from one to the other.

SECT. XLII.

OF THE DESCENT FROM MOUNT ETNA; OF ITS HEIGHT; AND OF THE ELECTRICITY OF THE AIR NEAR VOL. CANOS.

WE left the summit of the mountain about six c'clock, and it was eight at night before we reached Catania. We observed, both with pleasure and pain, the change of the climate as we descended. From the regions of the most rigid winter, we soon arrived at those of the most delightful spring. O first entering the forests, the trees were still bare as in December, not a single leaf to be seen; but after we had descended a few miles, we found ourselves in the mildest, and the softest of climates ; the trees in full verdure, and the fields covered with all the flowers of the summer; but as soon as we got out of the woods, and entered the torrid zone, we found the heats altogether insupportable, and suffered dreadfully from them before we reached the city.

On our arrival at Catania, we went immediately to bed, being exceedingly oppressed by the fatigue of our expedition ; but still more by the violent heat of the day.

Ætna has been often measured, but I believe never with any degree of accuracy; and it is really a shame to the society established in this place, called the Etnean Academy, whose original institution was to study the nature and operations of this wonderful mountain. It was my full intention to have measured it geometrically; but I am sorry to say, although this is both the seat of an academy and university, yet there was no quadrant to be had. Of all the

mountains I have ever seen, Ætna would be the easiest to measure, and with the greatest certainty, and perhaps the properest place on the globe to establish an exact rule of meusuration by the barometer. There is a beach of a vast extent, that begins exactly at the foot of the mountain, and runs for a great many miles along the coast. The sea-mark on this beach forms the meridian to the summit of the mountain. Here you are sure of a perfect level, and may make the base of your triangle of what length you please. But unfortunately this mensuration has never been executed, at least with any tolerable degree of precision.

Kircher pretends to have measured it, and to have found it 4000 French toises in height; which is more than any of the Andes, or indeed than any mountains upon earth. The Italian mathematicians are still more absurd. Some of them make it eight miles, some six, and some four.

Amici, the last, and I believe the best, who has made the attempt, reduces it to three miles, 264 paces ; but even this must be exceedingly erroneous; and probably the perpedicular height of Etna does not exceed 12,000 feet, or little more than two miles.

I own I did not believe we should find Ætna so high as it really is. I had heard indeed that it was higher than any of the Alps, but I never gave credit to it. How great then was my astonishment to find that the mercury fell almost two inches lower than I had ever observed it on the very highest of the ac-cessible Alps; at the same time I am persuaded there are many inaccessible points of the Alps, (particuJarly Mont Blane) that are still much higher than Etna.

The wind, and other circumstances, in a great measure prevented our electrical experiments, on which we had built not a little; however I found that round Nicolosi, and particularly on the top of Monpelieri, the air was in a very favorable state for electrical operations. Here the little pith-balls,