time to have thrown down that part of the cone next the fea, which would naturally have left it in its prefent ftate, and that the conical mountain, or ex:fting Vefuvius,has been raised by the fucceeding erup-. tions: all my obfervations confirm this opinion. I have feen ancient lavas in the plain on the other fide of Somma, which could never have proceeded from the prefent Vefuvius. Serao, a celebrated physician now living at Naples, in the introduction of his account of the eruption of Vefuvius in 1737 (in which account many of the phanomena of the volcano are recorded and very well accounted for) fays, that at the convent of Dominican friars, called the Madona del Arco, fome years ago, in finking a well, at a hundred feet depth a lava was difcovered, and foon after another, fo that in lefs than three bundred feet depth the lavas of four eruptions were found. From the fituation of this convent it is clear, beyond a doubt, that thefe lavas proceeded from the mountain called Somma, as they are quite out of the reach of the exifting volcano. From thefe circumstances, and from repeated obfervations i have made in the neighbourhood of Vefuvius, I am fure that no virgin foil is to be found there, and that all is compofed of different ftrata of erupted matter, even to a great depth below the level of the fea. In short, I have not any doubt in my own mind, but that this volcano took its rife from the bottom of the fea and as the whole plain between Vefuvius and the mountains behind Caferta, which is the best part of the Campagna Felice, is (under its good foil) compofed of burnt matter, I imagine the fea

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to have washed the feet of those mountains, until the fubterraneous fires began to operate, at a period certainly of a most remote antiquity.

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The foil of the Campagna Felice is very fertile I faw the earth opened in many places laft year in the midft of that plain, when they were feeking for materials to mend the road from Naples to Caferta. The ftratum of good foil was in general four or five feet thick: under which was a deep stratum of cinders,pumice, fragments of lava, and fuch burnt matter as abounds near Vefuvius and all volcanos. The mountains at the back of Caferta are moftly of a fort of limeftone, and very different from those formed by fire; though Signior Van Vitelli, the celebrated archite&t, has affured me, that in the cutting of the famous aqueduct of Caferta through these mountains, he met with fome foils, that had been evidently formed by fubterraneous fires. The high grounds which extend from Caftel a-Mare to the point of Minerva towards the ifland of Caprea, and from the promontory that divides the bay of Napies from that of Salerno, are of lime-ftone. The plain of Sorrento, that is bounded by these high grounds, beginning at the village of Vico, and ending at that of Maffa, is wholly compofed of the fame fort of tufa as that about Naples, except that the cinder or pumice-ftones intermixed in it are larger than in the Naples tufa. I conceive then that there has been an explosion in this fpot from the bottom of the fea. This plain, as I have remarked to be the cafe with all foils produced by fubterraneous fire, is extremely fertile; whilst

the

juft like thofe over Pompeii, and lavas like thofe of Vefuvius, compofe the whole foil of the country that remains to be defcribed.

the ground about it, being of another nature, is not fo. The island of Caprea does not fhew any figns of having been formed by fubterraneous fire, but is of the fame nature as the high grounds last mentioned, from which it has been probably detached by earthquakes, or the violence of the waves. Rovigliano, an island, or rather a rock, in the bay of Caftel-a-Mare, is likewife of lime-ftone, and feems to have belonged to the original mountains in its neighbourhood: in fome of these mountains there are alfo petrified fish and foil fhells, which I never have found in the mountains, which I fuppofe to have been formed by explotion. You have now, Sir, before you, the nature of the foil from Caprea to Naples. The foil on which this great metropolis ftands has been evidently produced by explofions, fome of which feem to have been upon the very fpot on which this city is built; all the high grounds round Naples, Paufilipo, Puzzole, Baïa, Mifenum, the islands of Procita and Ifchia, all appear to have been raised by explosion. You can trace ftill in many of thefe heights the conical fhape that was naturally given them at first, and even the craters out of which the matter iffued, though to be fure others of thefe heights have fuffered fuch changes by the hand of time, that you can only conjecture that they were raised in the like manner, by their composition being exactly the fame as that of thofe mountains, which ftill retain their conical form and craters entire A tufa, exactly refembling the fpecimen I took from the infide of the theatre of Herculaneum, layers of pumice intermixed with layers of good foil,

The famous grotto, anciently cut through the mountain of Paulipo to make a road from Naples to Puzzole, gives you an opportunity of feeing that the whole of that mountain is tufa. The first evident crater you meet with, after you have paffed the grotto of Paufilipo, is now the lake of Agnano; a fmall remain of the fubterraneous fire (which must probably have made the bafon for the lake, and raifed the high grounds which form a fort of amphitheatre round it) ferves to heat rooms, which the Neapolitans make great use of in fummer, for carrying off diverse diforders by a strong perfpiration. This place is called the Sudatorio di San Germano; near the prefent bagnios, which are but poor little hovels, there are the ruins of a magnificent ancient bath. About an hundred paces from hence is the Grotto del Cane. I fhall only mention, as a further proof of the probability that the lake of Agnano was a volcano, that vapours of a pernicious quality, as that in the Grotto del Cane, are frequently met with in the neighbourhood of Etoa and Vefuvius, particularly at the time of, before, and after great eruptions. The noxious vapour having continued in the fame force conftantly fo many ages, as it has done in the Grotto del Cane (for Pliny mentions this grotto), is indeed a circumftance in which it differs from the vapours near Vefuvius and Etna, which are not conftant; the cone forming the outude of this fuppofed volcano is fill perfect in many parts.

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Oppo

Oppofite to the Grotto del Cane, and immediately joining to the lake, rifes the mountain called Aftruni, which having, as I imagine, been thrown up by an explofion of a much latter date, retains the conical fhape and every fymp. tom of a volcano in much greater perfection than that I have been defcribing. The crater of Aftruni is furrounded with a wall to confine boars and deer (this volcano having been for many years converted into a royal chace). It may be about fix miles or more in circumference; in the plain at the bottom of the crater are two lakes, and in fome books there is mention made of a hot spring, which I never have been able to find. There are many huge rocks of lava within the crater of Aftruni, and fome I have met with alfo in that of Agnano; the cones of both these fuppofed volcanos are compofed of tufa and ftrata of loofe pumice, fragments of lava and other burnt matter, exactly resembling the ftrata of Vefuvius. Bartholomeus Fatias, who wrote of the actions of King Alphonfo the Firft (before the new mountain had been formed near Puzzole) conjectured that Aftruni had been a volcano. These are his words: Locus Neapoli quatuor millia paffuum proximus quem vulgo Liftrones vocant nos unum e Philegreis Campis ab ardore nuncupandum putamus. There is no entrance into the crater of either Aftruni or Agnano, except one, evidently made by art, and they both exactly correfpond with Strabo's defcription of avenues; the fame may be faid of the Solfaterra and the Monte Gauro, or Barbaro as it is fometimes called, which I fhall defcribe presently.

Near Aftruniand towards the fea

rifes the Solfatera, which not only retains its cone or crater, but much of its former heat. In the plain within the crater, fmoke iffues from many parts, as alfo from its fides; here, by means of stones and tiles, heaped over the crevices through which the fmoke paffes,they collect, in an aukward manner, what they call fale armoniaco; and from the fand of the plain they extract fulphur and alum. This fpot, well attended to,might certainly produce a good revenue, whereas I doubt if they have hitherto ever cleared 200l. a year by it. The hollow found produced by throwing a heavy ftone on the plain of the crater of the Solfaterra, seems to in• dicate that it is fupported by a fort of arched natural vault; and one is induced to think that there is a pool of water beneath this vault (which boils by the heat of a fubterraneous fire ftill deeper) by the very moift fteam that iffues from the cracks in the plain of the Solfaterra, which, like that of boiling water, runs off a fword or knife, prefented to it, in great drops. On the outfide, and at the foot of the cone of the Solfaterra, towards the lake of Agnano, water rushes out of the rocks, fo hot, as to raife the quickfilver in Fahrenheit's thermometer to the degree of boiling water, a fact of which I was myfelf an eye-witnefs. This place, well worthy the obfervation of the curious, has been taken little notice of; it is called the Pifciarelli. The common people of Naples have great faith in the efficacy of this water, and make much use of it in all cutaneous diforders. as well as for another diforder that prevails here. It seems to be împregnated chiefly with fulphur and alum.

When

When you approach your ear to the rocks of the Pifciarelli, from whence this water oozes, you hear a horrid boiling noife, which feems to proceed from the huge cauldron, that may be supposed to be under the plain of the Solfaterra. On the other fide of the Solfaterra, next the fea, there is a rock which has communicated with the sea, till part of it was cut away to make the road Puzzole; this was undoubtedly a confiderable lava that ran from the Solfaterra when it was an active volcano. Under this rock of lava, which is more than feventy feet high, there is a ftratum of pumice and afhes. This ancient lava is about a quarter of a mile broad; you meet with it abruptly before you come in fight of Puzzole, and it finishes as abruptly within about an hundred paces of the town. I have often thought that many quarries of ftone upon examination would be found to owe their origin to the fame caufe, though time may have effaced all figns of the volcano from whence they proceeded. Except this rock, which is evidently lava and full of vitrifications like that of Vefuvius, all the rocks upon the coaft of Baïa are of tufa.

I have obferved in the lava of Vefuvius and Etna, as in this, that the bottom as well as the furface of it was rough and porous, like the cinders or fcoriæ from an ironfoundery, and that for about a foot from the furface and from the bottom, they were not near fo folid and compact as towards the centre; which muft undoubtedly proceed from the impreffion of the air upon the vitrified matter whilft in fufion. I mention this circuftanee, as it may serve to point out true lavas

with more certainty. The ancient name of the Solfaterra was, Forum Vulcani, a strong proof of its ori. gin from, fubterraneous fire. The degree of heat that the Solfaterra has preferved for fo many ages, feems to have calcined the ftones upon its cone, and in its crater, as they are very white and crumble easily in the hottest parts.

We come next to the new mountain near Puzzole, which, being of fo very late a formation, preferves its conical fhape entire, and produces as yet but a very flender vegetation. It has a crater almost as deep as the cone is high, which may be near a quarter of a mile perpendicular, and is in fhape a regular inverted cone. At the bais of this new mountain (which is more than three miles in circumference) the fand upon the fea thore and even that which is washed by the fea itself, is burning hot for above the space of an hundred yards; if you take up a handful of the fand below water, you are obliged to get rid of it directly, on account of its intenfe heat.

I had been long very defirous of meeting with a good account of the formation of this new mountain, becaufe proving this mountain to have been raifed by mere explosion in a plain, would prove, at the fame time, that all the neighbouring mountains, which are compofed of the fame materials, and have exactly or in part the fame form, were raised in the like manner, and that the feat of fire, the caufe of thefe explosions, lies deep, which I have every reafon to think.

Fortunately, I lately found two very good accounts of the phænomena that attended the explosion, which formed the new mountain,

published a few months after the event. As I think them very cu- rious, and greatly to my purpose, and as they are rare, I will give you a literal tranflation of fuch extracts as relate to the formation of the Monte Nuovo. They are bound in one volume*.

The title of the firft is, Dell' Incendio di Pozzuolo, Marco Antonio delli Falconi all' Illuftriffima, Signiora Marchefa della Padula nel MDXXXVII.

At the head of the fecond is, ·Ragionamento del Terremoto, del Nuovo Monte, del Aprimento di Terra in Pozzuolo nell' Anno 1538, é della fignificatione d'eff. Per Pietro Giaçomo di Toledo; and at the end of the book, Stampata in Nap. per Giovanni Sulzthach Alemano, a 22di Genaro 1539, con gratio, é privilegio.

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"Firft then (fays Marco Anto"nio della Falconi) will I relate "fimply and exactly the operations "of nature, of which I was either myfelf an eye-witnefs, or as they were related to me by those who "had been witneffes of them. It "is now two years that there have been frequent earthquakes at "Pozzuolo, at Naples, and the "neighbouring parts; on the day "and in the night before the ap66 pearance of this eruption, above "twenty fhocks, great and small, 66 were felt at the above-mentioned places. The eruption made its appearance the 29th of Septem"ber 1538, the feast of St. Mi"chael the angel; it was on a "Sunday, about an hour in the "night and as I have been in"formed, they began to fee on "that spot, between the hot baths

"or fweating rooms, and Treper "66 gule, flames of fire, which firft "made their appearance at the "baths, then extended towards

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Trepergule, and fixing in the "little valley that lies between the "Monte Barbaro and the hillock "called del Pericolo (which was "the road to the lake of Avernys "and the bath) in a fhort time "the fire increased to such a de66 gree that it burst open the earth "in this place, and threw up fo great a quantity of afhes and pumice ftones mixed with water, as covered the whole country; "and in Naples a fhower of thefe “ashes and water fell great part of "the night. The next morning, "which was Monday, and the laft "of the month, the poor inha"bitants of Pozzuolo, ftruck with "fo horrible a fight, quitted their "habitations, covered with that "muddy and black fhower, which " continued in that country the "whole day, flying death, but "with faces painted with its co"lours, fome with their children "in their arms, fome with facks "full of their goods, others lead

66

ing an afs loaded with their "frightened family towards Na"ples, others carrying quantities "of birds of various forts that had "fallen dead at the time the erup"tion began, others again with "fith which they had found, and "were to be met with in plenty

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upon the fhore, the fea having "been at that time confiderably "dried up. Don Petro di Toledo, "Viceroy of the kingdom, with "many gentlemen, went to fee fo "wonderfulan appearance; Ialfo,

"having