Etna: A History of the Mountain and of its Eruptions

by G. F. Rodwell

For a short distance above Nicolosi, stunted vines are seen growing in black cinders, but these soon give place to a large tract covered with lava and ashes, with here and there patches of broom. There was no visible path, but the mules seemed to know the way perfectly, and they continued to ascend with the same easy even pace without any guidance, even after the sun had disappeared behind the western flank of the mountain. In fact, you trust yourself absolutely to your mule, which picks his way over the roughest ground, and rarely stumbles or changes his even step. I found it quite easy to write notes while ascending, and even to use a pocket spectroscope at the time of the setting sun. Subsequently we saw a man extended at full length, and fast asleep upon a mule, which was leisurely plodding along the highway. The same confidence must not however be extended to the donkeys of Etna, as I found to my cost a few days later at Taormina. Here the only animal to be procured to carry me down to the sea-shore, 800 feet below, was a donkey. It was during the hottest part of the day, and it was necessary to carry an umbrella in one hand, and comfortable to wear a kind of turban of many folds of thin muslin round one's cap. The donkey after carefully selecting the roughest and most precipitous part of the road, promptly fell down, leaving me extended at full length on the road, with the open umbrella a few yards off. At the same time the turban came unfolded, and stretched itself for many a foot upon the ground. Altogether it was a most comical sight, and it reminded me forcibly, and at the instant, of a picture which I once saw over the altar of a church in Pisa, and which represented S. Thomas Aquinas discomfiting Plato, Aristotle, and Averröes. The latter was completely overthrown, and in the most literal sense, for he was grovelling in the dust at the feet of S. Thomas, while his disarranged turban had fallen from him.

The district of lava and ashes above Nicolosi is succeeded by forests of small trees, and we are now fairly within the Regione Selvosa. At half-past 8 o'clock the temperature was 66°, at Nicolosi at 4 o'clock it was 80°. About 9 o'clock we arrived at the Casa del Bosco, (4,216 feet), a small house in which several men in charge of the forest live. Here we rested till 10 o'clock, and then after I had put on a great-coat and a second waistcoat, we started for the higher regions. At this time the air was extraordinarily still, the flame of a candle placed near the open door of the house did not flicker. The ascent from this point carried us 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 6,300 feet we entered the Regione Deserta, a lifeless waste of black sand, ashes, and lava; the ascent became more steep, and the air was bitterly cold. There was no moon, but the stars shone with an extraordinary brilliancy, and sparkled like particles of white-hot steel. I had never before seen the heavens studded with such myriads of stars. The milky-way shone like a path of fire, and meteors flashed across the sky in such numbers that I soon gave up any attempt to count them. The vault of heaven seemed to be much nearer than when seen from the earth, and more flat, as if only a short distance above our heads, and some of the brighter stars appeared to be hanging down from the sky. Brydone, in speaking of his impressions under similar circumstances says:

"The sky was clear, and the immense vault of heaven appeared in awful majesty and splendour. We found ourselves more struck with veneration than below, and at first were at a loss to know the cause, till we observed with astonishment that the number of the stars seemed to be infinitely increased, and the light of each of them appeared brighter than usual. The whiteness of the milky-way was like a pure flame that shot across the heavens, and with the naked eye we could observe clusters of stars that were invisible in the regions below. We did not at first attend to the cause, nor recollect that we had now passed through ten or twelve thousand feet of gross vapour, that blunts and confuses every ray before it reaches the surface of the earth. We were amazed at the distinctness of vision, and exclaimed together, 'What a glorious situation for an observatory! had Empedocles had the eyes of Galileo, what discoveries must he not have made!' We regretted that Jupiter was not visible, as I am persuaded we might have discovered some of his satellites with the naked eye, or at least with a small glass which I had in my pocket."

Brydone wrote a hundred years ago, but his idea of erecting an observatory on Mount Etna was only revived last year, when Prof. Tacchini the Astronomer Royal at Palermo, communicated a paper to the Accademia Gioenia, entitled "Della Convenienza ed utilita di erigere sull' Etna una Stazione Astronomico-Meteorologico." Tacchini mentions the extraordinary blueness of the sky as seen from Etna, and the appearance of the sun, which is "whiter and more tranquil" than when seen from below. Moreover, the spectroscopic lines are defined with wonderful distinctness. In the evening at 10 o'clock, Sirius appeared to rival Venus, the peculiarities of the ring of Saturn were seen far better than at Palermo; and Venus emitted a light sufficiently powerful to cast shadows; it also scintillated. When the chromosphere of the sun was examined the next morning by the spectroscope, the inversion of the magnesium line, and of the line 1474 was immediately apparent, although it was impossible to obtain this effect at Palermo. Tacchini proposes that an observatory should be established at the Casa Inglesi, in connection with the University of Catania, and that it be provided with a good six-inch refracting telescope, and with meteorological instruments. In this observatory, constant observations should be made from the beginning of June to the end of September, and the telescope should then be transported to Catania, where a duplicate mounting might be provided for it, and observations continued for the rest of the year. There seems to be every probability that this scheme will be carried out in the course of next year.

During this digression we have been toiling along the slopes of the Regione Deserta and looking at the sky; at length we 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 assures us that the Casa Inglesi is quite near, but the stoppages become so frequent that it seems a long way off; at length we dismount, and drag the mules after us, and after a toilsome walk the small lava-built house, called the Casa Inglesi, is reached (1.30 a.m., temperature 40° F.) It stands at a height of 9,652 feet above the sea, near the base of the cone of the great crater, and it 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. It consists of three rooms, containing a few deal chairs, a table, and several shelves like the berths of ships furnished with plain straw mattresses; there is also a rough fireplace. We had no sooner reached this house, very weary and so cold that we could scarcely move, than it was discovered that the courier had omitted to get the key from Nicolosi, and there seemed a prospect of spending the hours till dawn in the open air. Fortunately we had with us a chisel and a geological hammer, and by the aid of these we forced open the shutter serving as a window, and crept into the house; ten minutes later a large wood fire was blazing up the chimney, our eatables were unpacked, some hot coffee was made, and we were supremely comfortable.

The Casa Inglesi and Cone of Etna

At 3 a.m. we left the Casa Inglesi for the summit of the great crater, 1,200 feet above us, in order to be in time to witness the sunrise. Our road lay for a short distance over the upper portion of the Piano del Lago, and the walking was difficult. The brighter stars had disappeared, and it was much darker than it had been some hours before. 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 slopes at an angle of "45° or more" according to one writer, and of 33° according to another; probably the slope varies on different sides of the cone: we do not think that the slope much exceeds 33° anywhere on the side of the cone which we ascended. Fortunately there was no strong wind, and we did not suffer from the sickness of which travellers constantly complain in the rarefied air of the summit. We reached the highest point at 4.30 a.m., and found a temperature of 47° F.

When Sir William Hamilton ascended towards the end of June the temperature at the base of the mountain was 84° F., and at the summit 56° F. When Brydone left Catania on May 26th, 1770, the temperature was 76° F., Bar. 29 in. 8½ lines; at Nicolosi at midday on the 27th it was 73° F., Bar. 27 in. 1½ lines; at the Spelonca del Capriole (6,200 feet), 61° F., Bar. 26 in. 5½ lines; at the foot of the crater, temp. 33° F., Bar. 20 in. 4½ lines, and at the summit of the crater just before sunrise, temp. 27° F., Bar. 19 in. 4 lines.