1902 Encyclopedia > Etna

Etna




ETNA.. Mount Etna, one of the most celebrated volcanoes in the world, is situated on the eastern sea-board of Sicily. Its position was first accurately determined in 1814 by Captain Smyth, who found the longitude of the highest bifid peak of the great crater to be 15° east of Greenwich, and the latitude 37° 43' 31" N. These results have been very generally accepted by later writers.

There can be no doubt that the name of Etna—Alrva—is derived from aiJdut, to burn. This name was known to Hesiod. The more modern name Mongibello, by which the mountain is still commonly known to the Sicilians, is a combination of the Italian monte and the Arabic gibel. During the Saracenic occupation of Sicily (827-1090), Etna was called Gibel Uttamat, the mountain of fire; and the second portion of Mongibello is a relic of the Arabic name.
Historical References and Descriptions.—Etna is often alluded to by classical writers. By the poets it was feigned to be the prison of the giant Enceladus or Typhon, by others the forge of Hephaestus. The flames proceeded from the breath of Enceladus, the thunderous noises of the mountain were his groans, and when he turned upon his side, earthquakes shook the island. Pindar (522-442 B.C.), in his first Pythian Ode, for Hiero of iEtna, winner in the chariot race in 474 B.C., exclaims:—" He (Typhon) is fast bound by a pillar of the sky, even by snowy Etna, nursing the whole year's length her dazzling snow. Whereout pure springs of unapproach-able fire are vomited from the inmost depth : in the day-time the lava streams pour forth a lurid rush of smoke, but in the darkness a red rolling flame sweepeth rocks with uproar to the wide deep sea." iEschylus (525-456 B.C.) speaks also of the "mighty Typhon" (Prom. Vinctus). Thucydides (471-402 B.C.) alludes in the last lines of his third book to three early eruptions of the mountain. Many other early writers speak of Etna, among them Theocritus, Virgil, Ovid, Livy, Seneca, Lucan, Petronius, Dion Cassius, Strabo, Diodorus Siculus, and Lucilius junior. While the poets on the one hand had invested Etna with various supernatural attributes, and had made it the prison of a chained giant, and the workshop of a swart god, Lucretius and others endeavoured to show that the erup-tions and other phenomena of the mountain could be ex-plained by the ordinary operations of nature. These ideas were developed by Lucilius junior (the friend of Seneca, to whom he addressed his Qucestiones Naturales) in a poem consisting of 640 Latin hexameters, entitled Etna. Many of the myths developed by the earlier poets had their home upon the very sides of Etna :—Demeter, torch in hand, seeking Persephone; Acis and Galatea; Polyphemus and the Cyclops.

If we pass to more modern times we find mention of Etna by Dante, Petrarch, Cardinal Bembo, and other Middle Age writers. In 1541 Fazzello made an ascent of the mountain, which he briefly describes in the fourth chapter (entitled " De iEtna Monte et ejus ignibus ") of his work De Rebus Siculis. He also gives a brief history of the mountain. In 1591 Antonio Filoteo, who was born on Etna, published a work in Venice, entitled JEtnoz Topographia, Incendiorum JEtneeorum Historia, in which he describes an eruption which he witnessed in 1536. He asserts that the mountain was then (as now) divided into three " regions "o—the first very arid, rugged, uneven, and full of broken rocks; the second covered with forests; and the third cultivated in the ordinary manner. Of the height he says, " Ascensum triginta circiter millia passuum ad plus habet."

The great eruption of 1669 was described at length by the naturalist Borelli in the year of its occurrence. It also formed the subject of a paper in the Philosophical Tran-actions ; and a brief account of it was given by the earl of Winchelsea, English ambassador at Constantinople, who was returning home by way of the Straits of Messina at the time. As the eruption of 1669 was the most considerable eruption of modern times, it attracted a good deal of atten-tion, and was described by several eye-witnesses. A map in the Bibliotheque Nationale in Paris gives an imaginary view of the mountain during this eruption. It is the ear-liest map of the mountain which the library possesses, and is entitled " Plan du Mont Etna, commumement dit Mont Gibel, en ITsle de Scicille, et de t'jncedie arrive par un treblement de terre, le 8me Mars dernier 1669." Further, in the sacristy of the cathedral of Catania there is a curious wall-painting, which represents broad red streams of lava descending from the Monti Rossi and overwhelming the city. Towards the middle of the next century the mountain was ascended and described by Count D'Orville (1727), by the German Riedesel in 1767, and by Sir William Hamil-ton, the English ambassador at Naples, in 1769. During the twenty succeeding years it was described by Borch, Swinbourne, Denon, Spallanzani, Faujas de Saint-Fond, and Houel. The last, in his Voyage pittoresqtie dans les Deux Siciles, 1782-1786, has given a capital account of the mountain, accompanied by some excellent engravings. In 1776 a clever Irishman named Patrick Brydone published two volumes of a Tour in Sicily and Malta, in wdiich he describes at some length his ascent of Etna, and he further states as many facts concerning the history of the mountain as he could collect from the Canon Becuperc and others. His account is more complete than any which had appeared in English up to that time, and he is fre-quently quoted in every account of the mountain with which we have met.

It was reserved, however, for the Abate Francesco Ferrara, professor of physical science in the university of Catania, to write the first history of Etna which has any claim to com-pleteness. It is entitled Descrizione dell' Etna, con la storia delle eruzioni e il catalogo dei prodoiti. The first edition appeared in 1793, and a second was struck off at Palermo in 1818. It is illustrated by a map, and by some rather rough engravings. The author was bom upon the mountain, and was witness to some of its grandest phenomena. His work has evidently been to a great extent a labour of love. It is full of personal observations, while it embodies the principal results of other observers, and furnishes the foundation of all that has since been written about Etna. During 1814-16 Captain Smyth, acting under the direction of the lords of the Admiralty, made a survey of the coast of Sicily, and carefully deter-mined the latitude and longitude of Etna; he also accu-rately measured the height and examined the surroundings of the mountain. His results were published in 1824, and are still often quoted as the most accurate which exist. In 1824 Dr Giuseppe Gemellaro, who lived all his life upon Etna, and made it his constant study, published an " Historical and Topographical Map of the Eruptions of Etna from the Era of the Sicani to the year 1824." In it he shows the extent of the three regions, Goltivata, Selvosa, and Deserta; he lays down the places of the minor cones to the number of seventy-four; and he traces the course of the various lava streams which have flowed from them and from the great crater. About 1847 Baron Sartorius von Waltershausen commenced a minute survey, and a com-plete examination of the mountain, both geologically and otherwise. He was assisted by a brother professor, and by two Sicilians, and their labours resulted in the production of a fine atlas of Etna, which even in its incomplete form costs ¿£12. Owing to the death of Von Waltershausen, the work was never quite completed, but, as it is, it supplies the most exhaustive history of any one mountain on the face of the earth. Sir Charles Lyell visited Etna three times (in 1824,1857, 1858), and he has embodied the results of his researches in a paper communicated to the Royal Society, and in a lengthy chapter in his Principles of Geology. His investigations have contributed much to our know-ledge of the geological characteristics of the mountain.

The most important recent contribution to our knowledge of Etna has been the fine map of the Stato Maggiore con-structed by order of the Italian Government between 1864 and 1868. It embraces the whole of Sicily, and is laid down on the unusually large scale of 1 in 50,000, or P266 inch to the mile. The portion relating to Etna and its immediate surroundings occupies four sheets. Plate VII. is a reproduction of this map on a smaller scale. All the small roads, paths, and rivulets are introduced ; the minor cones and monticules are placed in their proper positions; and the elevation of the ground is given at short intervals of space over the map. A careful examination of this map shows us that it represents the first accurate survey of the entire mountain. It shows us that distances, areas, and heights have been repeatedly misstated, the minor cones misplaced, and the trend of the coast-line misrepresented.

Height.—The height has been often determined. The earlier writers had very exaggerated notions on the subject, and a height of three and even four miles has been assigned. Brydone, Saussure, Shuckburgh, and others obtained ap-proximations to the present height; it must be borne in mind, however, that the cone of a volcano is liable to variations in height at different periods, and a diminution of more than 300 feet has occurred during the course of a single eruption of Etna, owing to the falling of the cone of cinders into the crater. During the last sixty years, how-ever, the height of the mountain has been practically con-stant. In 1815 Captain Smyth determined it to be 10,874 feet. In 1826 Sir John Herschel, who was unacquainted with Smyth's results, estimated it at 10,872^ feet. The new map of the Stato Maggiore gives 3312'61 metres = 10,867'94 feet. The radius of vision from the summit is very variously stated. Smyth gives it as 150'7 miles, and this we are inclined to adopt as the nearest approach to the truth, because he was an accurate observer, and he made careful corrections both for error of instruments and for refraction. This radius gives an horizon 946-4 miles in circumference, and an included area of 39,900 square miles,—an area larger than that of Ireland.

Boundaries.—The road which surrounds the mountain is carried along its lower slopes, and is 87 miles in length. By reference to the map it will be seen that it passes through the towns of Paterno, Biancavilla, Aderno, Bronte, Bandazzo, Linguaglossa, Giarre, and Aci Beale. By some writers it is considered to define the base of the mountain, which is hence said, most erroneously, to have a circumference of 87 miles ; but the road frequently passes over high beds of lava, and it winds considerably. It is about 10 miles from the crater on the north, west, and east sides of the mountain, increasing to 16 miles at Paterno (S.W.). The elevation on the north and west flanks of the mountain is nearly 2500 feet, rising at its maximum elevation to 3852 feet, while on the south it falls to 1500 feet, and on the east to within 50 feet of the level of the sea. It is quite clear, therefore, that this road cannot be taken as the limit of the base. The natural boundaries of Etna are the rivers Alcantara and Simeto on the north, west, and south, and the sea on the east to the extent of 23 miles of coast, along which lava streams have been traced, sometimes forming headlands several hundred feet in height. The base of the mountain, as defined by these boundaries, is said to have a circumference of " at least 120 miles ; " an examination of the new map, however, proves that this is overestimated. If we take the sea as the eastern boundary, the river Alcantara (immediately beyond which Monte di Mojo, the most northerly minor cone of Etna, is situated) as the northern boundary, and the river Simeto as the boundary on the east and south, we obtain an approximate circumference of 91 miles for the base of the mountain. In this estimate the small sinuositie3 of the rivers have been neglected, and the southern circuit has been completed by drawing a line from near Paterno to Catania, because the Simeto runs for the last few miles of its course through the plain of Catania, quite beyond the most southerly lava stream.

Area.—The area of the region inclosed by these boundaries is approximately 480 square miles. Beclus gives the area of the mountain as 1200 square kilometres => 461 square miles (Nouvelle Geographic Universelle, 1875).

Population.—There are 2 cities, Catania and Aci Reale, and 63 towns or villages on Mount Etna. It is far more thickly populated than any other part of Sicily or Italy; for while the population of Italy per square kilometre is 90, and of Sicily 88, that of the habitable zone of Etna is 550. No less than 300,000 persons live on the mountain. Thus, with an area rather larger than that of Bedfordshire (462 square miles), it has more than double the population ; and with an area equal to about one-third that of Wiltshire, the population of the mountain is greater by nearly 50,000.





General Aspect.—The general aspect of Etna is that of a pretty regular cone with very gentle slopes covered with vegetation, except near the summit. The regularity is broken on the east side by a slightly oval valley, four or five miles in diameter, called the Val del Bue. It com-mences about two miles from the summit, and is bounded on three sides by nearly vertical precipices from 3000 to 4000 feet in height. The bottom of the valley is covered with lavas of various dates, and several minor craters have from time to time been upraised from it. Many eruptions have commenced in the immediate neighbourhood of the Val del Bue, and Lyell believes that there once existed a crater of permanent eruption in the valley. Mount Vesuvius might be almost hidden away in the Val del Bue.

Regions.—The Val del Bue is altogether sterile, having been the frequent scene of both fire and flood, but the mountain at the same level, as its middle and lower portions, is on its other sides clothed with forests. The surface of the mountain has been divided into three zones or regions'— the Piedemontana or Coltivata, the Selvosa or Nemorosa, and the Beserta or Biscoperta.

The lowest of these, the Cultivated Region, yields in abundance all the ordinary Sicilian products. The surface soil, which consists of decomposed lavas, is extremely fertile, although of course large tracts of land are covered by recent lavas, or by those which decompose but slowly. In this region the vino flourishes, and abundance of corn, olives, pistachio nuts, mulberries, oranges, lemons, figs, and other fruit-trees. The breadth of the Coltivata varies; it terminates at an approximate 'height of 2000 feet. A circle drawn with a radius of ten miles from the crater roughly defines the upward limit of this region. The elevation of points on the circumference of such a circle is 2310 feet on the north near Bandazzo, 2145 feet on the south near Nicolosi, 600 feet on the east near Mascali, and 1145 feet on the west near Bronte. The breadth of the cultivated zone is about two miles on the north, east, and west, and nine or ten miles on the south, if we take for the base of the mountain the limits proposed above.

The Woody Region commences where the Cultivated Begion ends, and it extends as a belt of varying width to an approximate height of 6300 feet. It is terminated above by a circle having a radius of about a mile and a half from the great crater. There are fourteen separate forests in this region,—some abounding with oak, beech, pine, and poplar, others with the chestnut, ilex, and cork tree. The celebrated Castagno di Cento Cavalli, one of the largest and oldest trees in the world, is in the forest of Carpinetto, on the east side of the mountain, five miles above Giarre. The breadth of the Regione Selvosa varies considerably : in the direction of the Val del Bue it is very narrow, while elsewhere it often has a breadth of from six to eight miles.

The Desert Region is embraced between the limit of 6300 feet and the summit. It occupies an area of about ten square miles, and consists of a dreary waste of black sand, scorias, ashes, and masses of ejected lava. In autumn, winter, and spring it remains permanently covered with snow, and even in the height of summer snow may be found in certain rifts near the summit.

Minor Cones.—A remarkable feature of Etna is the large number of minor cones which are scattered over its sides. They look small in comparison with the great mass of the mountain, but in reality some of them are of large dimen-sions. Monte Minardo, near Bronte, the largest of the minor cones, is still 750 feet in height, although its base has been raised by modern lava streams which have flowed around it. There are 80 of the more conspicuous of the minor cones, but Von Waltershausen has mapped no less than 200, within a ten-mile radius of the crater, neglecting many monticules of ashes. According to Reclus, there are 700 minor cones, while Jukes asserts that there are 600; these statements undoubtedly include the most insignificant monticules, and also the bocche and boecarelle, from which lava or fire has issued. If these be included, no doubt the above numbers are not exaggerations. The only large and important minor cone which has been raised during the historical period is the double mountain known as Monti Rossi, from the red colour of the cinders which compose it. This was raised from the plain of Nicolosi during the eruption of 1669 ; it is 450 feet high, and two miles in circumference at the base. In a line between the Monti Rossi and the great crater 33 of the more important minor cones may be counted, and Captain Smyth was able to discern 50 from an elevated position on the mountain. Many of them are covered with vegetation, as the names Monte Faggi, Monte Ilice, Monte Zappini, indicate. In manyinstances the names have not been happily chosen, and several cones in different parts of the mountain bear the same name: Monte Arso, Monte Nero, Monte Rosso, Monte Frumento, are the most common of these duplicates.

Ascent of the Mountain.—The best period for making the ascent of Etna is between June and September, after the melting of the winter snows, and before the falling of the autumnal rains. In winter there are frequently nine or ten miles of snow stretching from the summit downwards, the paths are obliterated, and the guides sometimes refuse to accompany travellers. Moreover violent storms often rage in the upper regions of the mountain, and the wind acquires a force which it is difficult to withstand, and is at the same time piercingly cold. The writer of this article made the ascent of the mountain in the month of August 1877, accompanied by a courier and a guide. The weather was fine and bright, and there had been no rain for more than three months. The temperature in the shade at Catania, and generally along the eastern coast of Sicily, was a mean of 82° Fahr. The party left Catania soon after mid-day, and drove to Nicolosi, 12 miles distant, and 2288 feet above the sea. The road for some distance lay through a very fertile district; on both sides there were corn-fields and vineyards, and gardens of orange and lemon trees, figs and almonds, growing in the decomposed lava. The road passes through several small villages,—Pasquali, Gravina, and Mascalucia—the last a town of 4000 inhabi-tants. Soon after this the Monti Rossi are seen apparently close at hand, the village of Torre di Grifo is passed, and the road then enters a nearly barren district, covered with the lava of 1537. The only prominent vegetation is a peculiar tall broom {Genista Etnensis), which flourishes here. Nicolosi was reached at half-past 4 o'clock, and after dinner in the one room of the very primitive inn, a start was made for the summit at 6 o'clock. For a short distance above Nicolosi stunted vines are seen growing in black ashes, but these soon give way to a large tract covered with lava and ashes, with here and there patches of broom. At half-past eight o'clock P.M. the temperature was 66° Fahr. About 9 o'clock the Casa del Bosco (4216 feet) was reached, at the foot of Monte Rinazzi, a small house in which several men live who have charge of the forest. After an hour's rest, the ascent of the higher regions was commenced, a great-coat and a double waistcoat being put on as a protection against the increasing cold. The air was extraordinarily still at this time; the flame of a candle placed near the open door of the Casa del Bosco did not flicker. The ascent from this point led through forests of pollard oaks, in which it was quite impossible to see either a path or any obstacles which might lie in one's way. The guide carried a lantern, and the mules seemed well accustomed to the route. At about 6300 feet above the sea the Regione Deserta was entered, a lifeless waste of black sand, ashes, and lava; the ascent now became more steep, and the air was bitterly cold. There was no moon, but the stars shone in extraordinary numbers and with wonderful brilliancy, sparkling like particles of white-hot steel. The milky way gleamed like a path of fire, and meteors flashed across the sky in such numbers as to baffle any attempt to count them. The vault of heaven seemed to be much nearer than when seen from the earth, and- also more flat, and as if only a short distance overhead, and some of the brighter stars appeared to be hanging down from the sky The idea of erecting an observatory on Mount Etna was brought forward last year, when Professor Tacchini, the astronomer-royal at Palermo, communicated a paper to the Accademia Gioenia, entitled Bella Gonvenienza ed utilita di erigere sulF Etna una stazione Astronomico-Meteoroiogico, in which he refers to the extraordinary blueness of the sky as seen from the higher regions of Etna, and the appearance of the sun in a telescope, which is " whiter and more tranquil " than when seen from below; moreover the spectroscopic lines are defined with wonderful distinctness.

Toiling along the slopes of the Regione Deserta, at length the travellers reach the Piano del Lago, or Plain of the Lake, so called because a lake produced by the melting of the snows existed here till 1607, when it was filled up by lava. The air is now excessively cold, and a sharp wind is blowing. Progress is very slow, the soil consists of loose ashes, and the mules frequently stop. The guide maintains that the Casa Inglesi is quite near, but the stoppages become so frequent that it seems a long way off; at length it becomes necessary to dismount, and after a toilsome walk the small lava-built house called the Casa Inglesi is reached (1.30 A.M., temperature 40° Fahr.) It stands at a height of 9652 feet above the sea, near the base of the cone of the great crater. The Casa Inglesi takes its name from the fact that it was erected by the English officers stationed in Sicily in 1811. It has suffered severely from time to time from the pressure of snow, and from earthquakes, but it was thoroughly repaired in 1862, on the occasion of the visit of Prince Humbert, and is now in tolerable preservation. At 3 A.M. the Casa Inglesi is left for the summit of the great crater, 1200 feet above, in order to be in time to witness the sunrise. The road lay for a short distance over the upper portion of the Piano del Lago, and the walking was very difficult. The brighter stars had disappeared, and it was much darker than it had been some hours earlier. The guide led the way with a lantern. The ascent of the cone was a very stiff piece of work. It consists of loose ashes and blocks of lava, and it slopes at an angle of " 45° or more," accord-ing to one writer, and of 33°, according to another. Pro-bably the slope varies on different sides of the cone; on the side the ascent described was made the 45° certainly seems the more probable. Fortunately there was no strong wind, and no experience of the sickness of which travellers constantly complain in the rarefied air of the summit. The highest point was reached at 4.30 A.M., temperature 47° Fahr. Steam and sulphurous acid issued from the ground, and the cinders were so hot in some places that it was necessary to choose a cool place to sit down on. A thermometer inserted just beneath the soil from which steam issued registered 182° Fahr. Nearly all the stars had now faded away. The vault of heaven was a pale blue, becoming a darker and darker grey towards the west, where it was nearly black Just before sunrise the sky had the appearance of an enormous arched spectrum extremely extended at the blue end. Above the place where the sun would presently appear there was a brilliant red, shading off in the direction of the zenith to orange and yellow; the latter was succeeded by pale green, this by a long stretch of pale blue, then darker blue, and dark grey, ending opposite to the rising sun with black. This effect was quite distinct; it lasted some minutes, and was very remarkable. It was succeeded by the usual rayed appear-ance of the rising sun, and at ten minutes to 5 o'clock the upper limb of the sun was seen above the mountains of Calabria. Examined by the spectroscope, the Fraunhofer lines were extremely distinct, particularly two lines near the red end of the spectrum. The top of the mountain was now illuminated, while all below was in comparative dark-ness, and a light mist floated over the lower regions. The party was so fortunate as to witness a phenomenon which is not always visible, viz., the projection of the shadow of the mountain across the island, an hundred miles away. The shadow appeared to be vertically suspended in space, at or beyond Palermo, and to be resting on a slightly misty atmosphere; it gradually sank until it reached the surface of the island, and as the sun rose, the shadow of course approached nearer and nearer to the base of the mountain. In a short time the flood of light destroyed the fine effects of light and shadow which were at first visible. The mountains of Calabria appeared very close; the east coast of Sicily could be traced until it ended at Cape Passaro and turned to the west, forming the southern boundary of the island, while to the west distant mountains appeared.

The crater was then examined,—a vast abyss nearly 1000 feet in depth, shut in by precipitous sides. Its dimensions vary, but it is now between two and three miles in circum-ference. Sometimes it is nearly full of lava, at other times it appears to be bottomless. At the present time it is like an inverted cone ; its sides are covered with incrustations of sulphur and ammonia salts, and jets of steam perpetually issue from crevices in its sides. Near the summit was found a deposit several inches in thickness of a white substance, apparently lava decomposed by the hot effluent gases. Hydrochloric acid is said to frequently issue from the crater; the most abundant gases appeared to be sul-phurous acid and steam. The interior of the crater reminds one in many respects of the Solfatara near Puzzuoli. During the descent from the cone various specimens of ash and cinder were collected—some red, others black and very vesicular, others highly crystalline, some pale pink. The steep slope of the cone was well shown by the fact that although the surface is either extremely rugged owing to the accumulation of masses of lava, or soft and yielding on account of the accumulation of cinders, a large mass of lava, set rolling near the summit, rushes down with increasing velocity until it bounds off to the plain below.





A striking feature presented during the descent from the mountain was the apparent nearness of the minor cones below, and of the villages at the base of the mountain. The latter seemed to be painted on a vertical wall, and although from ten to fifteen miles distant, they appeared almost within a stone's throw. This curious effect, which has often been observed before, is due to atmospheric refraction.

The different specimens of lava were found to present a wonderful similarity of structure and composition. The main constituents are olivine, magnetite, and felspar. The crystals of the latter are much larger in some specimens than in others. Sometimes olivine prevails, sometimes felspar. A specimen of lava of 1535 found near Borello was ground until it was sufficiently transparent to be examined under the microscope by polarized light. It was found to contain good crystals of augite and olivine, and well striated labradorite and magnetite.

Eruptions.—A list of all the eruptions of Etna from the earliest times, has been given by several writers, notably by Ferrara in his Descrizione dell' Etna, and by Gemellaro.
The first eruption within the historical period probably happened in the 7th century B.C.; the second occurred in the time of Pytha-goras. The third eruption, which occurred in 477 B.C., is men-tioned by Thucydides, and it must be the eruption to which Pindar and iEschylus allude. An eruption mentioned by Thucydides occurred in the year 426 B.C. An outburst of lava took place from Monte di Mojo, the most northerly of the minor cones of Etna, in 396 B.C., and following the course of the river Acesines (now the Alcantara) entered the sea near the site of the Greek colony of Naxos (now Capo di Schiso). We have no record of any further eruption for 256 years, viz., till the year 140 B.C. Six years later an eruption occurred, according to Orostus and Julius Obsequens; and Fulvius Flaccus and the same authorities men-tion an eruption in the year 126 B.C. Four years later Katana was nearly destroyed by a new eruption, 122 B.C. An erup-tion, of which we possess no details, occurred during the civil war between Ctesar and Pompey, 49 B.C. Livy speaks of an eruption and earthquake which took place (43 B.C.) shortly before the death of Ctesar, which it was believed to portend. In 38 B.C. and 32 B.C. eruptions occurred. The next eruption of which we hear is that mentioned by Suetonius in his life of Caligula. This was in 40 A.D. An eruption is stated to have occurred in 72 A.D. after which Etna was quiescent for nearly two centuries, but in the year 253, in the reign of the emperor Decius, a violent erup-tion lasting 9 days occurred. According to Carrera and Photius, an eruption occurred in the year 420. We now find no further record for nearly 400 years. Geoffrey of Viterbo states that an eruption occurred in 812, when Charlemagne was in Messina. After another long interval, in this case of more than three centuries and a half, the mountain again entered into eruption. In February 1169 one of the most disastrous eruptions on record occurred. A violent earthquake, which was felt as far as Eeggio, destroyed Catania in the course of a few minutes, burying 15,000 persons beneath the ruins. It was the vigil of the feast of St Agatha, and the cathedral of Catania was crowded with people, who were all buried beneath the ruins, together with the bishops and forty-four Benedictine monks. The side of the cone of the great crater towards Taormina, fell into the crater. According to Nicola Speziale, there was a great eruption from the eastern side of the mountain in 1181. Lava descended from the eastern side of the mountain in 1285 ; in 1329 Nicola Speziale was in Catania, and he witnessed a very violent eruption, of which he has left us an account. On the evening of June the 28th, about the hour of vespers, Etna was strongly con-vulsed, terrible noises were emitted, and flames issued from the south side of the mountain. A new crater, Monte Lepre, opened near the Val del Bue, above the rock of Musarra, and emitted large quantities of dense black smoke. Soon afterwards a torrent of lava poured from the crater, and red hot masses of rock were pro-jected into the air. Four years after the last eruption, it is recorded by Silvaggio that a fresh outburst took place. A manuscript preserved in the archives of the cathedral of Catania mentions an eruption which occurred on the 6th of August 1371, which caused the destruction of numerous olive groves near the city. An erup-tion which lasted for twelve days commenced in November 1408. A violent earthquake in 1444 caused the cone of the mountain to fall into the great crater. An eruption of short duration, of which we have no details, occurred in 1447. After this Etna was quiescent for 89 years. Cardinal Bembo and Fazzello mention an eruption which occurred towards the close of the 15th century. In March 1536 a quantity of lava issued from the great crater, and several new apertures opened near the summit of the mountain and emitted lava. A year later, in May 1537, a fresh outburst oeeurred. A number of new mouths were opened on the south slope of the mountain near La Fontanelle, and a quantity of lava was emitted, which Mowed, in the direction of Catania, destroying a part of Mcolosi, and St Antonio. In four days the lava had run fifteen miles. The cone of the great crater suddenly fell in, so as to become level with the Piano del Lago. The height of the mountain was thus diminished by 320 feet. Three new craters opened in November 1566, on the north-east slope of the mountain. In 1579,1603,1607,1610, 1614, and 1619, unimportant eruptions occurred. In February 1633 Nicolosi was partially destroyed by a violent earthquake, and in the following December earthquakes became frequent around the mountain. In 1646 a new mouth opened on the north-east side, and five years later several new mouths opened on the west side of che mountain, and poured out vast volumes of lava, which threatened to overwhelm Bronte. We have a more detailed account of the eruption of 1669 than of any previous eruption. It was observed by many men of different nations, and we find accounts of it in the Philosophical Transactions, and in several separate narra-tives in French and Italian. Perhaps the most accurate and com-plete description is that given by Alfonso Borelli, professor of mathematics in Catania. The eruption was in every respect one of the most terrible on record. On the 8th of March the sun was obscured, and a whirlwind blew over the face of the mountain ; at the same time earthquakes were felt, and they continued to increase in violence for three days, at the end of which Nicolosi was con-verted into a heap of ruins. On the morning of the 11th a fissure nearly 12 miles in length opened in the side of the mountain, and extended from the Piano di St Leo to Monte Frumento, a mile from the summit. The fissure was only six feet wide, but it seemed to he of unknown depth, and a bright light proceeded from it. Six mouths opened in a line with the principal fissure, and emitted vast volumes of smoke, accompanied by low bellowing, which could be heard 40 miles off. Towards the close of the day a crater opened about a mile below the others, and ejected red-hot stones to a considerable distance, and afterwards sand and ashes, which covered the country for a distance of 60 miles. The new crater soon vomited forth a torrent of lava, which presented a front of 2 miles. It encircled Monpilieri, and afterwards flowed towards Belpasso, a town of 8000 inhabitants, which was speedily destroyed. Seven mouths of fire opened around the new crater, and in three days united with it, forming one large crater 800 feet in diameter. The torrent of lava had continued to flow, and it destroyed the town of Mascalucia on the 23rd of March. On the same day the crater cast up great quantities of sand, ashes, and scoria?, and formed above itself the great double coned hill called Monti Rossi, from the red colour of the ashes of which it is mainly composed. On the 25th very violent earthquakes occurred, and the cone of the great central crater was shaken down into the crater, for the fifth time since the first century A.D. The original current of lava had divided into three streams, one of which destroyed San Pietro, the second Camporotondo, and the third the lands about Mascalucia, and afterwards the village of Misterbianco. Fourteen villages were afterwards destroyed, and the lava made its way towards Catania. At Albanello, twTo miles from the city, it undermined a hill covered with corn fields, and carried it forward a considerable distance ; a vineyard was also seen to be floating on its fiery surface. When the lava reached the walls of Catania it accumulated without progression, until it rose to the top of the wall, 60 feet in height, and it then fell over in a fiery cascade, and overwhelmed a part of the city. Another portion of the same stream threw down 120 feet of the wall, and flowed through the city. On the 23rd of April the lava reached the sea, which it entered as a stream 600 yards broad and 40 feet deep. The stream had moved at the rate of 13 miles in twenty days, but as it cooled it moved less quickly, and during the last 23 days of its course it only moved two miles. On reaching the sea the water of course began to boil violently, and clouds of steam arose, carrying with them particles of scoria?. The volume of lava emitted during this eruption amounted to many millions of cubic feet. Ferrara considers that the length of the stream was at least 15 miles, while its average width was between 2 and 3 miles, so that it covered at least 40 square miles of surface.

For a few years after this terrible eruption Etna was quiescent, but in 1682 a new mouth opened on the east side of themountain, and lava issued from it and rushed down the precipices of the Val del Bue. In 1688 a torrent of lava burst from an opening in the great cone, and in the following year lava was emitted from a mouth in the Val del Bue. Early in January 1693 clouds of black smoke were poured from the great crater, and loud noises, resembling the dis-charge of artillery, were heard. A violent earthquake succeeded, and Catania was shaken to the ground, burying 18,000 of its inhabitants. It is said that in all fifty cities and towns were destroyed in Sicily, together with from 60,000 to 100,000 inhabitants. Lava was emitted from the crater, the cone of which was lowered by the eruption. In the following year Etna again entered into eruption. In March 1702 three mouths opened in the Contrada del Tri-foglietto, near the head of the Val del Bue. In 1723, 1732, 1735, 1744, and 1747 slight eruptions occurred. Early in the year 1755 Etna began to show signs of disturbance ; a great column of black smoke issued from the crater, from which forked lightning was frequently emitted. Loud detonations were heard, and two streams of lava issued from the crater. A new mouth opened near Bocca di Musarra in the Val del Bue, four miles from the summit, and a quantity of lava was ejected from it. An extraordinary flood of water descended from the Val del Bue, carrying all before it, and strewing its path with large blocks. Eecupero estimated the volume of water at 16,000,000 cubic feet, probably a greater amount than could be furnished by the sudden melting of all the winter's snow on the mountain. It formed a channel 2 miles broad, and in some places thirty-four feet deep, and it flowed at the rate of a mile in a minute and a half during the first twelve miles of its course. Lyell con-siders that the flood was probably produced by the melting not only of the winter's snow, but also of older layers of ice, which were suddenly liquefied by the permeation of hot steam and lava, and which had been previously preserved from melting by a deposit of sand and ashes, as in the case of the ancient glacier found near the summit of the mountain in 1828. In November 1758, a smart shock of earthquake caused the cone of the great crater to fall in, but no eruption occurred at the time. In 1759, 1763, 1766, and 1780 eruptions occurred, and on the 18th of May in 1780 a fissure opened on the south-west side of the mountain, and extended from the base of the great crater for seven miles, terminating in a new mouth, from which a stream of lava emanated. This encountered the cone of Palmintelli in its course, and separated into two branches, each of which was about 4000 feet wide. Other mouths opened later in the year, and emitted larger quantities of lava, while in 1781 and 1787 there were slight eruptions. Five years afterwards a fresh outburst occurred ; earthquakes were prevalent, and vast volumes of smoke were carried out to sea, seeming to form a gigantic bridge between Sicily and Africa. A torrent of lava flowed towards Aderno, and a second flowed into the Val del Bue as far as Zuccolaro. A pit called La Cistcrna, forty feet in diameter, opened in the Piano del Lago near the great cone, and ejected smoke and masses of old lava saturated with water. Several mouths opened below the crater, and the country round about Zafi'arana was desolated. In 1797, 1798, 1799, 1800, 1802, 1805, and 1808 slight eruptions occurred. In March 1809 no less than twenty-one mouths of fire opened between the summit of the mountain and Castiglione, and two years afterwards more than thirty mouths opened in a line running eastwards from the summit for five miles. They ejected jets of fire, accompanied by much smoke. In 1819 five new mouths of fire opened near the scene of the eruption of 1811 ; three of these united into one large crater, and poured forth a quantity of lava into the Val del Bue. The lava flowed until it reached a nearly perpendicular precipice at the head of the valley of Calanna, over which it fell in a cascade, and being hardened by its descent, it was forced against the sides of the tufaceous rock at the bottom, so as to produce an extraor-dinary amount of abrasion, accompanied by clouds of dust, worn off by the friction. Mr Scrope observed that the lava flowed dt the rate of about a yard an hour nine months after its emission. Eruptions occurred in 1831, 1832, 1838, and 1842. Near the end of the following year, fifteen mouths of fire opened near the crater of 1832, at a height of 7000 feet above the sea. They began by discharging scoria? and sand, and afterwards lava, which divided into three streams, the two outer of which soon came to a stand-still, while the central stream continued to flow at the rapid rate of 180 feet a minute, the descent being an angle of 25°. The heat at a distance of 120 feet from the current was 90° F. A new crater opened just above Bronte, and discharged lava which threatened the town, but it fortunately encountered Monte Vittoria, and was diverted into another course. While a number of the inhabi-tants of Bronte were watching the progress of the lava, the front of the stream was suddenly blown out as by an explosion of gunpowder. In an instant red hot masses were hurled in every direction, and a cloud of vapour enveloped everything. Thirty-six persons were killed on the spot, and twenty survived but a few hours. The great crater showed signs of disturbance, by emitting dense volumes of smoke, and loud bellowings, also quantities of volcanic dust saturated with hydrochloric acid, which destroyed the vegetation wherever it fell. A very violent eruption, which lasted more than nine months, commenced on the 26th of August 1852. It was first witnessed by a party of six English tourists, who were ascending the mountain from Nicolosi in order to witnesss the sunrise from the summit. As they approached the Casa Inglesi, the crater commenced to give forth ashes and flames of fire. In a narrow defile they were met by a violent hurricane, which over-threw both the mules and the riders, and urged them toward the precipices of Val del Bue. They sheltered themselves beneath some masses of lava, when suddenly an earthquake shook the moun-tain, and the mules in terror fled away. They returned on foot towards daylight to Nicolosi, fortunately without having sustained injury. In the course of the night, many bocchc del fuoco opened in that part of the Val del Bue called the Balzo di Trifoglietto,

and a great fissure opened at the base of Giannieola Grande, and a crater was thrown up, from which for seventeen days showrers of sand and scoriae were ejected. During the next day a quantity of lava flowed down into the Val del Bue, branching off so that one stream flowed to the foot of Monte Finocchio, while the other flowed to Monte Calanna. The eruption continued with abated violence during the early months of 1853, and did not fully cease till May 27th. The entire mass of lava ejected is estimated to be equal to an area six miles long by two miles broad, with an average depth of about twelve feet. In October 1864 frequent shocks of earthquake were felt by the dwellers on Etna. In January 1865 clouds of smoke were emitted by the great crater, and roaring sounds were heard. On the night of the 30 th a violent shock was felt on the north-east side of the mountain, and a mouth opened below Monte Frumcnto, from which lava was ejected. It flowed at a rate of about a mile a day, and ultimately divided into two streams. By March 10th the new mouths of fire had increased to seven in number, and they were all situated along a line stretch-ing down from the summit. The three upper craters gave forth loud detonations three or four times a minute. Since 1865 the mountain has been in a quiescent state.
It will be seen from the foregoing account that there is a great similarity in the general character of the erup-tions of Etna. Earthquakes presage the outburst; loud explosions are heard; rifts and bocche del fuoco open in the sides of the mountain : smoke, sand, ashes, and scoriae are discharged; the action localizes itself in one or more craters; cinders are thrown out and accumulate around the crater in a conical form ; ultimately lava rises through the new cone, frequently breaking down one side of it where there is least resistance, and flowing over the surrounding country. Then the eruption is at an end. Out of the 78 eruptions mentioned above, a comparatively small number have been of extreme violence, while many have been of a slight and harmless character.
According to Lyell, Etna is rather older than Vesuvius, —perhaps of the same geological age as the Norwich Crag. At Trezza, on the eastern base of the mountain, basaltic rocks occur associated with fossiliferous Pliocene clays. The earliest eruptions of Etna are older than the Glacial period in Central and Northern Europe. If all the minor cones and monticules could be stripped from the mountain, the diminution of bulk would be extremely slight. Lyell concludes that, although no approximation can be given of the age of Etna, " its foundations were laid in the sea in the newer Pliocene period." From the slope of the strata from one central point in the Val del Bue he further con-cludes that there once existed a second great crater of per-manent eruption.

Such are the principal facts in the history of a volcano, justly called famoso, immense, terribile, which has excited the wonder of all nations in all ages of the history of the world. (G. F. E.)



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