them from the bottom. But in the lower country, it divides into smaller streams, running with less rapidity; and yet with such violence, that it drives the strongest stone fences before it, and lighting trees like torches, affords a most extraordinary though dismal spectacle.

On December 23, 1770, about two in the morning, a violent shock of an earthquake was felt near mount Vesuvius. Some time after, some countrymen being at work, four or five miles from it, perceived the ground near them on a sudden heave and gape, like dough that is rising. At the same time they observed smoke issuing from the clefts. They immediately fled, till they thought they were out of danger. And then looking back, saw the water of a cistern, near which they had been at work, spout out to a great height. This was succeeded by a large discharge of fiery matter from the mouth of the cistern, and from four other openings, attended with a dreadful noise and explosion of burning stones. On a sudden all the fiery streams united in one, flowed impetuously down the mountain, and gliding quick as lightning, presently covered all the adjacent lands. Meantime the whole mountain shook greatly, and a fixed pillar of smoke issued out of the main aperture, which rising to a certain height, then dissolved into ashes, and fell like rain all over the mountain. At the same time an immense quantity of burning stones was thrown out.

The fiery stream continued running down the mountain, the whole night between the 23d and 24th. Houses, gardens, and every thing in its way, were consumed. And ashes were still thrown out, which lay deep on the ground for several miles about, and reached as far as the sea coast.

On the 25th also there was an eruption of liquid fire, with a shower of stones, and a huge noise. In several parts this stream was fifty spans deep. The mountain meantime continued to roar, and thick ashes fell like rain over the whole country.

On the 26th, both the mountain itself and the hills lately produced, sent forth stones and ashes, the bellowings were still heard, but with intermissions: and out of the five apertures, two only continued to emit stones, ashes, and fire.

On the 27th, only one fiery stream remained, and that began to cool, and to lose its brightness, appearing more dusky, like burning coals ready to go out. On the 28th, the stream ran much slower, and no more burning stones were cast out. The height of the chief hill raised thereby was about two hundred spans; and its circumference about two hundred paces. The motion of the lava in front was very slow; it gained ground on

T

ascended about a league, we felt the ground shake under us and heard a terrible noise in the bowels of the earth, just as if it was going to burst open. At the same time there appeared on all sides chinks, out of which' issued bluish flames, with a strong suffocating smell. This made us turn back, for fear of being burnt to ashes. But we had scarce proceeded thirty yards back, before a black cloud of smoke ascended out of the mountain, obscured the light of the sun, and covered us so thick, that we could not see each other. Our fears increased every step we took; for behind us came flames of fire, with showers of ashes and pumice stones, which fell as thick as hail. This dreadful storm was attended with horrible noises, and we expected every moment, the earth would open and swallow us up. This added wings to our flight, so that in a quarter of an hour we got to the bottom of the mountain.

12. There are volcanos likewise in many of the American islands: and a very eminent one in Guadaloupe. The summit of this constantly emits smoke, and sometimes flames. It rises very high, in form of a cone, above the chain of the mountains that occupy the centre of the island. Near the foot of it are three springs, the waters of which are so hot as to boil eggs in three minutes. The neighbouring ground smokes, and is full of brown earth like the dross of iron. But the chief place where the smoke issues out, is higher up, at the foot of a steep bank, about fifty yards in breadth. Here no grass is to be seen; nothing but sulphur and calcined earth. The ground is full of deep cracks, which emit much smoke, and where you may hear the sulphur boil. But the stench of it is intolerable. The ground is loose, so that you may thrust a cane up to the head. And when you draw it up, it will be as hot as if you had plunged it into slacking lime.

On the plain top of the hill is another funnel, that opened some years since, and emits nothing but smoke. Here are abundance of large and deep chinks, which doubtless burned in former times. In the middle of this plain is a very deep abyss. It is said there was once a great earthquake in the island, and that the Brimstone Hill (so they call it) then took fire. It was probably then this abyss was opened. It is between two craggs that rise above the mountain and on the north side answers to the great cleft, which goes down above a thousand feet perpendicular, is more than twenty feet broad, and penetrates above a hundred paces in the flat. So that in this place the mountain is fairly split, from the top down to the basis of the

cone.

On this plain you may see the clouds gather below, and hear the thunder rumble under your feet. The great cavern is under the cleft, and was doubtless formed by the same earthquake that

But, to consider this point a little more minutely. As some earthquakes are owing to fire, so are some to air, others to water, and others to earth itself. 1. The earth itself may be the occasion of its own shaking, when the root or basis of some large mass being worn away, that mass sinks in by its own weight, and causes a concussion of all the neighbouring parts. 2. Subterraneous waters wash away the foundations of hills, and eat far under the earth. By this means many earthquakes have been occasioned, and whole cities swallowed up. This was undoubtedly the cause of the great earthquake at Port Royal, and of that which swallowed up Lima. 3. Air pent up in the bowels of the earth, if it be at any time rarefied and expanded, will struggle for vent with incredible force, and thereby both shake and tear the earth. 4. But the usual cause of the most violent earthquakes is sulphur, or some other inflammable matter taking fire in the cavities of the earth, and bursting through whatever opposes.

There are scarce any countries that are much subject to earthquakes, which have not some burning mountain. And whenever any earthquake happens, this is constantly in flames. Indeed were it not that these vents thus disgorge the fire, it would make far greater havoc than it does; probably it would make the whole country for a vast space round quite uninhabitable.Yea, so beneficial are these, that we do not want instances of countries frequently annoyed by earthquakes, which, upon the breaking out of a volcano, have been wholly delivered from them.

Perhaps what causes most earthquakes of this kind is the pyrites, or iron stone, which will take fire of itself. The earth, we know, abounds in cavities, which are at certain times full of inflammable vapours. Thus the damps in mines shew, which being fired, every thing as in an earthquake, only in a less degree. And the pyrites only, of all known minerals, yields this inflammable vapour. Nor is any mineral or ore whatever sulphureous, but what is more or less mixed with the pyrites.But probably the pyrites of the burning mountains, is more sulphureous than ours. It is likewise in far greater quantities in all the countries round the Mediterranean than in England: a plain reason why earthquakes are so much more frequent and more violent there.

An artificial earthquake may be made thus: add twenty pounds of sulphur to twenty of iron filings; mix and temper these with water, so as to form a mass of the consistence of a firm paste; bury this three or four feet under ground. In six or seven hours time, the earth will begin to tremble, crack and smoke, and fire and flame will burst through. So that there only wants a sufficient quantity of this matter, to produce a