Sir William Hamilton

“ From the observations I have made upon Mount Etna, Vesuvius, and its neighbourhood, [Pg 92] I dare say, that, after a careful examination, most mountains, that are or have been Volcanos, would be found to owe their existence to subterraneous fire; the direct reverse of what I find the commonly received opinion.
Nature, though varied, is certainly in general uniform in her operations; and I cannot conceive that two such considerable Volcanos as Etna and Vesuvius should have been formed otherwise than every other considerable Volcano of the known world. ”

“ Turning towards the place of the eruption, you saw mountains of smoak, part of which was very black and part very white, [Pg 131] rise up to a great height; and in the midst of the smoak, at times, deep-coloured flames burst forth with huge stones and ashes, and you heard a noise like the discharge of a number of great artillery. It appeared to me as if Typheus and Enceladus from Ischia and Etna with innumerable giants, or those from the Campi Phlegrei (which, according to the opinions of some, were situated in this neighbourhood) , were come to wage war again with Jupiter. ”

“ I had the pleasure of seeing a well sunk, a few days ago, near my villa, which is, as you know, at the foot of Vesuvius, and close by the sea-side. At twenty-five feet below the level of the sea, they came to a stratum of lava, and God knows how much deeper they might have still found other lavas. The soil all round the mountain, which is so fertile, consists of stratas of lavas, ashes, pumice, and now-and-then a thin stratum of good earth, which good earth is produced by the surface mouldering, and the rotting of the roots of plants, vines, &c. ”

“ Did the matter which proceeds from a Volcano in an eruption come from so inconsiderable a depth as they imagine, that part of the mountain situated above their supposed seat of the fire must necessarily be destroyed, or dissipated in a very short time: on the contrary, an eruption usually adds to the height and bulk of a Volcano; and who, that has had an opportunity of making observations on Volcanos, does not know, that the matter they have emitted for many ages, in lavas, ashes, smoak, &c. ”

“ As the lavas of Etna are very commonly fifteen and twenty miles in length, six or seven in breadth, and fifty feet or more in depth; you may judge, Sir, of the prodigious quantities of matter emitted in a great eruption of this mountain, and of the vast cavities there must necessarily be within its bowels. The most extensive lavas of Vesuvius do not exceed seven miles in length. The operations of nature on the one mountain and the other are certainly the same ”

“ May not subterraneous fire be considered as the great plough (if I may be allowed the expression) , which Nature makes use of to turn up the bowels of the earth, and afford us fresh fields to work upon, whilst we are exhausting those we are actually in possession of, by the frequent crops we draw from them? Would it not be found, upon enquiry, that many precious minerals must have remained far out of our reach, had it not been for such operations of Nature? ”

“ The ashes were carried as far as Calabria by the force of the winds, [Pg 140] burning up in their passage the grass and high trees, many of which were borne down by the weight of them. An infinity of birds also, and numberless animals of various kinds, covered with this sulphureous mud, gave themselves up a prey to man. Now this eruption lasted two nights and two days without intermission, though, it is true, not always with the same force, but more or less: when it was at its greatest height, even at Naples you heard a noise or thundering like heavy artillery when two armies are engaged. ”

“ What a proof we have here of the great changes the earth we inhabit is subject to! What is now the Solfaterra, we have every reason to suppose to have been originally thrown up by a subterraneous explosion from the bottom of the sea. That it was long an existing Volcano, is plain, from the ancient currents of lava, that are still to be traced from its crater to the sea, from the strata of pumice and erupted [Pg 176] matter, of which its cone, in common with those of other Volcanos, is composed, and from the testimony of many ancient authors. ”

“ The famous grotto anciently cut through the mountain of Pausilipo, to make a road from Naples to Puzzole, gives you an opportunity of seeing that the whole of that mountain is tufa. The first evident crater you meet with, after you have passed the grotto of Pausilipo, is now the lake of Agnano; a small remain of the subterraneous fire (which must probably have made the bason for the lake, and raised the high grounds which form a sort of amphitheatre round it) serves to heat rooms, which the Neapolitans make great use of in summer, for carrying off diverse disorders, by a strong perspiration. ”

“ The Abbate Giulio Cesare Bracini, in his account of the eruption of Vesuvius, in 1631, says, that the height of the column of smoak and ashes, taken from Naples by a quadrant, was upwards of thirty miles. Though such uncertain calculations demand but little attention; yet, by what I have seen, I am convinced, that in great eruptions the ashes are sent up to so great a height as to meet with extraordinary currents of air, which is the most probable way of accounting for their having been carried to so great a distance in a few hours. ”

“ It is very true that many of them in going up could not be seen, on account of the dark smoak; but, when they returned from the smoaky heat, they shewed plainly where they had been, by their strong smell of fetid sulphur, just like stones that have been thrown out of a mortar, and have passed through the smoak of inflamed gunpowder. The mud was of the colour of ashes, and at first very liquid, then by degrees less so; and in such quantities, that in less than twelve hours, with the help of the abovementioned stones, a mountain was raised of a thousand paces in height. ”

“ There is no sign of a crater on the top of this mountain, which rises almost to a sharp point: time, and other accidents, may be reasonably supposed to have worn away this distinctive mark of its having been formed by explosion, as I have seen to be the case in other mountains, formed evidently by explosion, on the flanks of Etna and Vesuvius. Strabo, in his 5th book, upon the subject of this island, quotes Timæus, as having said, that, a little before his time, a mountain in the middle of Pithecusa, called Epomeus, was shook by an earthquake, and vomited flames. ”

“ I shall only add, that Vesuvius is quiet at present, though very hot at top, where there is a deposition of boiling sulphur. The lava that ran in the Fossa Grande during the last eruption, and is at least two hundred feet thick, is not yet cool; a stick, put into its crevices, takes fire immediately. On the sides of the crevices are fine crystalline salts: as they are the pure salts, which exhale from the lava that has no communication with the interiour of the mountain, they may perhaps indicate the composition of the lava. ”

“ We passed through the inferior district of the mountain, called by its inhabitants La Regione Piemontese. It is well watered, exceedingly fertile, and abounding with vines and other fruit trees, where the lava, or, as it is called there, the sciara, has had time to soften, and gather soil sufficient for vegetation, which, I am convinced from many observations, unless assisted by art, does not come to pass for many ages [18] , perhaps a thousand years [Pg 58] or more; the circuit of this lower region, forming the basis of the great Volcano, is upwards of one hundred Italian miles. ”

“ Till now, the ascent had been so gradual (for the top of Etna is not less than thirty miles from Catania, from whence the ascent begins) as not to have been the least fatiguing; and if it had not been for the snow, we might have rode upon our mules to the very foot of the little mountain, higher than which the Canon our guide had never been: but as I saw that this little mountain was composed in the same manner as the top of Vesuvius, which, notwithstanding the smoak issuing from every pore, is solid and firm, I made no scruple of going up to the edge of the crater ”

“ The soil of the Campagna Felice is very fertile; I saw the earth opened in many places last year in the midst of that plain, when they were seeking for materials to mend the road from Naples to Caserta. The stratum of good soil was in general four or five feet thick; under which was a deep stratum of cinders, pumice, fragments of lava, and such burnt matter as abounds near Vesuvius and all Volcanos. The mountains at the back of Caserta are mostly of a sort of lime-stone, and very different from those formed by fire ”

“ The ancients, in describing Vesuvius, never mention two mountains. Strabo, Dio, Vitruvius, all agree, that Vesuvius, in their time, shewed signs of having formerly erupted [33] , and the first compares the [Pg 112] crater on its top to an amphitheatre. The mountain now called Somma was, I believe, that which the ancients called Vesuvius: its outside form is conical; its inside, instead of an amphitheatre, is now like a great theatre. I suppose the eruption in Pliny's time to have thrown down that part of the cone next the sea, which would naturally have left it in its present state ”

“ A tufa, exactly resembling the specimen I took from the inside of the theatre of Herculaneum, layers of pumice intermixed with layers of good soil, just like those over Pompeii, and lavas like those of Vesuvius, compose the whole soil of the country that remains to be described. ”

“ In this part of the mountain, are the finest horned cattle in Sicily; we remarked in general, that the horns of the Sicilian cattle are near twice the size of any we had ever seen; the cattle themselves are of the common size. We passed by the lava of the last eruption in the year 1766, which has destroyed above four miles square of the beautiful wood abovementioned. The mountain raised by this eruption abounds with sulphur and salts, exactly resembling those of Vesuvius; specimens of which I sent some time ago to the late Lord Morton. ”

“ Nicola, on which there is at present a convent of hermits, was called by the ancients Epomeus; it is as high, if not higher, than Vesuvius, and appears to me to be a section of the cone of the ancient and principal Volcano of the island, its composition being all tufa or lava. The cells of the convent abovementioned are cut out of the mountain itself; and there you see plainly that its composition no way differs from the matter that covers Herculaneum, and forms the Monte Nuovo. ”

“ There is no spot, I believe, that could afford a more ample field for curious observations, than the island of Ischia, called Enaria, Inarime, and Pithecusa, by the ancients. I have visited it three times; and this summer passed three weeks there, during which time I examined, with attention, every part of it. Ischia is eighteen [Pg 152] miles in circumference: the whole of its soil is the same as that near Vesuvius, Naples, and Puzzole. There are numberless springs, hot, warm, and cold [41] , dispersed over the whole island, the waters of which are impregnated with minerals of various sorts ”

“ We passed over vallies of snow, that never melts, except there is an eruption of lava from the upper crater, which scarcely ever happens; the great eruptions are usually from the middle region, the inflamed matter finding (as I suppose) its passage through some weak part, long before it can rise to the excessive height of the upper region, the great mouth on the summit only serving as a common chimney to the Volcano. In many places the snow is covered with a bed of ashes, thrown out of the crater, and the sun melting it in some parts makes this ground treacherous ”

“ It is, that we are apt to judge of the great operations of Nature on too confined a plan. When first I came to Naples, my whole attention, with respect to natural history, was confined to Mount [Pg 162] Vesuvius, and the wonderful phænomena attending a burning mountain: but, in proportion as I began to perceive the evident marks of the same operation having been carried on in the different parts above described, and likewise in Sicily in a greater degree, I looked upon Mount Vesuvius only as a spot on which Nature was at present active ”

“ The sea of the Bay of Naples, being particularly agitated, and swelling some hours before the arrival of a storm, may very probably force itself into crevices, leading to the bowels of the Volcano, and, by causing a new fermentation, produce those explosions and grumblings.
[2] These ashes destroy the leaves and fruit, and are greatly detrimental to vegetation for a year or two; but are certainly of great service to the land in general, and are among the principal causes of that very great fertility which is remarkable in the neighbourhood of Volcano's. ”

“ I do not pretend to say, that a just estimate can be formed of the great age of Volcanos from [Pg 99] this observation; but some sort of calculation might be made: for instance, should an explosion of pumice cover again the spot under which Pompeii is buried, the stratum of rich soil abovementioned would certainly lie between two beds of pumice; and if a like accident had happened a thousand years ago, the stratum of rich soil would as certainly have wanted much of its present thickness, as the rotting of vegetables, manure, &c. is ever increasing a cultivated soil. ”