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yet remarked that the pavement of own proper weight, as by the alRome is also composed of the same fistance of the wind and rains, and materials. I may say as much of lastly, by the roofs and timbers the pavement of the greater part giving way. This mixture being of the ancient Roman highways, united by the infiltration of the and perhaps of all those of which waters, has condensed in process any vestiges are remaining from of time, and formed a kind of Rome to Naples, as well as on the fand-stone, more or less hard, but road from Naples to Puzzuoli and every where easy to be dug through. Cumea. In short, it is the fame Such is also the foil of the heights with the Appian way, which still which command Naples to the subfifts, and makes a part of the north and to the west, viz. those high road from Rome to Naples. of Capo di Monte, the castle of This antique pavement is entirely St. Helena, and the Charter-house, composed of lava.

but more particularly the steep hill We shall be less furprised at this, which we fee on the sea-shore, as when we come to know that the we go out of the city to the West, foundations of the houses in the Such again is the soil of the emisubterranean city of Herculaneum, nence into which is dug that fabuilt now 2000 years ago, are pure mous fubterranean antiquity, above lava. This is sufficient to deter- half a mile long, known under mine a question discuffed in the the name of Paulilyppo's grotto. academy of belles-lettres, and All the mountains and hillocks proves evidently that the great in the invirons of Naples will vieruptions of Vesuvius are not all fbly appear on an examination to of them pofterior to that which be nothing more than a mass of swallowed up the city of Hercu- various forts of matter, vomited laneum. But though this city is, forth by volcanos which no longer in fact, buried under several strata exist, and whose eruptions, anteof lava, properly so called, yet we rior to history, have probably must not imagine that its ftreets, formed the ports of Naples and its squares, and its buildings, are Puzzuoli. But it is not in Naples covered with lava : were this the only, and its neighbourhood, that cafe, neither the pick-axe nor chif- I have found the like kinds of fel would be able to penetrate there. matter. My eyes being accuftomThe matter with which the interiored to distinguish the different emaparts of the city are filled, has nations of Vesuvius, and especially never been either fused or liquid. the lava, under all its various apIt is only one immense mass of pearances, discovered it, beyond cinders, earth, gravel, fand, coal, room for doubt, on the whole road pumice-stones, and other materials, from Naples to Rome, and even launched forth through the mouth at the very gates of the latter, of the volcano, at the time of its sometimes pure, sometimes mixed, explofion, and fallen again in heaps and combined with other materials. in all the circumjacent parts. The 1. All the interior part of the moun. at frit buried all the houses ;-by tain of Frascati, on which stood degrees they penetrated into the Cicero's Tufculum, the chain of, interior parts, as well by their hills extending from Frascati to


Grotto-Ferrata, Caftel Gandol as acquainted with, when I made fo, and as far as the lake of the tour of Naples. He asserts.' Albano, a great part of the moun that all islands and mountains tain of Tivoli, together with those wherein are found marine bodies, of Caprarola, Viterbo, &c. are and of course the continents which composed of several beds of cal- ferve as bases to these mountains, cined stones, pure cinders, scorias, have all sprung out of the bosom gravel, other materials resembling of the deep, by the efforts of fubdross of iron, baked earth, and terranean fires. History furnishes lava, properly fo called ; in short, him with proofs for a pretty conall like those of which the foil of 'fiderable number : the rest he conPortici is composed, and those cludes by induction. His asserwhich issue out of the fides of tion, the truth of which I am unVesuvius, under so many different willing to deny, is too general to forms. One may distinguish by be completely proved : I confine the

eye all these several substances : my own to simple facts, and draw the cinders may be discovered both from thence only the necessary conby their colour and taste. It is sequences. When I see in an eleimpoffible for any one, who exa- vated plain a circular bason furmines with attention the produc- rounded with calcined rocks, the tions of. Vesuvius, not to observe verdure with which the neighboura perfect resemblance between them ing fields are covered imposes not and those which we meet, every on me; I instantly perceive there step we take, on the road from the ruins of an ancient volcano,

Naples, to Rome, and from Rome as I should perceive beneath the ; to Viterbo, Loretto, &c. It fol- snow itself the traces of an extin

lows then neceffarily, that all this guished fire, on seeing an heap of part of Italy-has been overturned cinders or coal. If there be a by volcanos. These plains, which breach in this circle, I usually find at present appear smiling and fer out by following the declivity of tile, covered with olive-trees, mul- the ground, the traces of a rivulet, berry-trees, and vineyards, as are or the bed of a torrent, which also to this very day even the sides seems; as it were, hollowed in the of Vesuvius, have formerly been, rock; and this rock when examinlike them, over-run with burning ed closely, appears frequently to waves, and like them bear, not be nothing more than lava, proonly in their bowels, but even on perly so called. If the circumfetheir furface, the veftiges of those rence of the bason has no breach,. torrents of fire, the billows of the rain and spring waters which which are at present grown cold assemble there and have no issue, again and condensed: irresistible generally form a lake in the very testimonies of vast conflagrations mouth of the volcano. anterior to all historical monu The representation alone, on a ments.

topographical chart, of the lake I pretend not to revive the system of Albano, with its steep fides and of Lazzaro Moro, a Venetian au circle roughened with rocks, callthor, whose work (printed at Veed to my remembrance the lake nice in 1740) I was not fo much of Quilotoa, which I have elle


where described*, and whole waters years time both Lima and Quito, fometimes exhale fumes of fire. two capital cities of Peru, became A few days after, the fight of the the victims of these two kinds of lake of Albano itself, and the cal volcanos. The chain of those of cined matter with which its banks the Apennine, which divides the are powdered, left me no room to continent of Italy, in like manner doubt any longer of its origin. I from north to fouth, and extends saw manifestly the profound

tunnel as far as Sicily, presents us ftill of the shaft of an ancient volcano, with a pretty great number of viin the mouth of which the waters fible fires under different forms; had accumulated themselves. Its in Tuscany, the exhalations of eruption, of which history makes Firenzuola, and the warm baths-of no mention, must have been anterior Pisa; in the ecclefiaftical state, to the foundation of Rome, and those of Viterbo, Norcia, Norcera, even of Alba, from whence this &c. in the kingdom of Naples, lake has taken its name, a period those of Ischia, Solfaterra, and amounting to near 3000 years.

Vesuvius; in Sicily, and the neighAt the fight of the traces of fire bouring illes, Ætna or Moant diffused in the environs of the lakes Gibel, with the volcanos of Liof Borfello, Rerfiglione, and Brac- pari, Stromboli, &c. But other ciano, or the road from Rome to volcanos of the same chain being Florence, I had formed the same either extinct or exhausted from conjectures, before I had seen ei time immemorial, have left only ther Vesuvius or the matter which fome remains behind; which, alit vomits forth. I pass the same though they may not always strike judgment by analogy on the lake at the first sight, are not at all less of Perugio, and several others in distinguishable to attentive eyes. the interior parts of Italy, which In fort, the earthquakes which I know only by the map.

have at various times overturned In short, I look upon the Apen- feveral of the cities of Italy and nine as a chain of volcanos, like Sicily, that which fwallowed up that of the Cordilleras of Peru the city of St. Euphemia in 1638, and Chili, which runs from north and of which Kirker has drawn so to fouth, the whole length of pathetic a picture, that which deSouth America, from the province #troyed Catano in 1693, that which of Quito to the Terra Magella- opened the gulfs of Palermo in nica. The course of the volcanos 1718, that which fince the reading of the Cordilleras is interrupted: of this memoir has overturned Sya great number of them are either racuse, recall to my remembrance extinguished or smothered; but the difailers of Valparaiso, Callao, several still remain actually burn Lima, and Quito, in South Ameing. The old ones also frequently rica, and close the parallel between revive, and sometimes new ones the Cordilleras of Italy and those are kindled even in the bottom of of Peru : the marks of resem the fea; nor are their effects, on blance between them are but too that account, less fatal. In a few In a few itriking.

Multiplication • Historical Journal of a Voyage to the Equator, p. 61,

the same twig.

Multiplication of species in the vea Parkinson, in his Paradisus,

getable kingdom, instanced in the gives it a name of his own (nuxnectarine..

perfica) which may be given with

as much propriety to the peach as I Was visiting, laft fummer, at the nectarine. He says, Mathiolus

Thomas Wood's, Efq; at Lit- mentions it; but I have not that tleton, near Sunning, in Middle- author. fex; who taking me into his gar It is, I think, probable, that den, told he would fhew me a great some ingenious people, having obcuriosity: and immediately lead- ferved this lufus naturæ, and taken ing me to a large peach-tree, he buds from the nectarine branch, thewed me, on one little twig, a

and inserted them into proper peach and nectarine growing close stocks, thus began the race of together.

nectarines,' and afterwards increafThis amazed me: I had, indeed, ed the forts by fowing stones.-I before heard, from persons of un have a young nectarine-tree, that doubted probity, that a particular came up from an accidental stone branch of a peach-tree had some that fowed itself, and bore fruit times bore nectarines : but here this year. the wonder was increased, for two I was at first led to think, that diftinct different fruits are seen on this uncommon production hap

pened from the similitude of the I knew my worthy friend, Mr. organs of generation in the peach Wood, was a gentleman of too and nectarine. Being both species much honour and veracity to de- of the fame genus, and growing ceive me.-Yet, to satisfy my cu

in the fame garden, I thought the riosity, I carefully examined the prolific powder of the nectarine tree, and found not the least reason might impregnate the ovary of the to fufpect any fallacy.--The twig, peach, and, from that accident, for fo I muft' call it from its small- the fruit might be changed to a ness, projected from the stem of the nectarine : but this will not actree about the length of my finger; count for the first phænomenon of on one fide was a fair rough peach, the kind, which, if my conjecture and close on the other side of the above, concerning the origin of fame twig was a fair smooth shining the nectarine, is true, must have nectarine.

happened before any trees bearing Having strictly related the fact, nectariues only were in being, I shall submit the cause of this I am informed, that the like phænomenon to the judgment of mixt production happened at lord

Wilmington's at Chiswick. This conclusion, however, I And thus in orchards amongst draw from it, that the peach is the apple-trees, 'a mixture of fruit mother of the nectarine; and what hath been observed on the fame confirms my notion, is, that I have tree, fupposed by the sporting of not found yet an ancient Latin name the farina.--See Vol. X. of Marfor the nectarine, which could tin's Abridgment of the Philos. scarce happen, if it was

not a Trans, more modern fruit than the peach.


the ball and not on the inside, will Experiments to prove that water is squeeze it into less compafs*. And

not incompresible; by John CAN- by this compression of the ball the TON, M. A. and F. R. S. from mercury and water will be equally Part 11. of the Philosophical raised in the tube: but the water Transactions for the year 1762. is found, by the experiments above

related, to rise to of an inch HAVING procured a fmall glass more than the mercury by se

tube of about two feet in moving the weight of the atmolength, with a ball at one end of sphere. it of an inch and a quarter in dia In order to determine how much meter ; I filled the ball and part water is compressed by this or a of the tube with mercury; and greater weight, I took a glafs ball keeping it with a Farenheit's ther- of about an inch and iš in diamometer, in water which was fre-. meter, which was joined to a cylinquently stirred, it was brought drical tube of four inches and to exactly to the heat of fifty degrees; in length, and diameter abontos and the place where the mercury of an inch; and by weighing the stood in the tube, which was about quantity of mercury that exactly 6 inches above the ball, was filled the whole length of the tube; carefully marked. I then raised I found that the mercury in 27 of the mercury, by heat, to the top an inch of the tube, was the of the tube, and sealed the tube 100,oooth part of that contained hermetically; and when the mer- in the ball, and with the edge of cury was brought to the fame de- a file, I divided the tube accordgreat of heat as before, it ftood in ingly. the tube rio of an inch higher This being done, I filled the ball than the mark.

and part of the tube with water The same ball, and part of the exhausted of air ; and left the tube tube being filled with water ex open, that the ball, whether in hausted of air, instead of the mer rarefied or condensed air, might cury; and the place where the wa- always be equally pressed within ter stood in the tube when it came and without, and therefore not alto rest in the heat of 50 degrees tered in its dimensions. Now by being marked, which was about placing this ball and tube under fix inches above the ball; the wa

the receiver of an air - pump, I ter was then raised by heat till it could see the degree of expansion filled the tube; which being sealed of the water, answering to any de, again, and the water brought to gree of rarefa&tion of the air; and the heat of 50 degrees as before, by putting it into a glass receiver it ftood in the tube féo of an inch of a condensing engine, I could above the mark.

see the degree of compresion of Now the weight of the atmo- the water, answering to any desphere (or about 73 pounds avoir- gree of condensation of the air. dupoize) prefing on the outside of But great care must be taken in


* See an account of experiments made with glass balls by Mr. Hooke, (afterwards Dr. Hooke) in Dr. Birch's Fhistory of the Royal Society, vol. I. p. 127.

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