October 6, 1^92] 



NA TURE 



543 



characteristic pirre-shape of explosive eruptions, and 

 illuminated by lightnings. 



After half an hour this phenomenon ceased, and the 

 smoke-plume was swept away by the higher currents of 

 the atmosphere. I was able to ascertain in my excursion 

 to the summit of Etna, in company with Mr. Rudler, 

 curator of the Museum of Practical Geology of London, 

 that the central crater was much modified by the short 

 eruption. It presented two mouths, separated by a par- 

 tition, whilst its upper edge was much broken down, so 

 that it was enlarged. The ejected materials were com- 

 posed of fragments of very much altered lavas that fell 

 chiefly to the westward. During the night the ground 

 was in a state of tremor, and at 2.45 a.m. of the 9th, a 

 strong shock of earthquake was felt all over the Etnean 

 region, producing slight damage to the walls of buildings. 



Towards 1.20 p.m., without any further shock sensible 

 in the inhabited regions, the southern flank of Etna was 



which is to the south of the new craters, it divided in two 

 principal branches and precipitated itself on the plain from 

 which rises Monte Gemmeilaro, forming three cascades 

 of living fire. It here spread out, and the two branches, 

 directing their course to the south, threatened Nicolosi, 

 Belpasso, and Pedara. The more eastern ramification, 

 when it reached the neighbourhood of Monte Albano, 

 began to slow down and was already on the 1 2th advancing 

 about two metres per hour, but increasing the breadth of 

 its front and its thickness. On the other hand the 

 western branch, which was invading the cultivated land,^ 

 advanced in the steeper ground over fifty metres the 

 hour, as I observed in my first visit on July 11. 

 This stream was of a bright red colour, slightly 

 covered by scoria. Near Monte Concilio it had filled up 

 a valley, assuming a thickness of over 40 m. From Monte 

 Ardicazzi we had presented to our view an immense 

 expanse of fire from which rose crests and hills all in- 



FiG. I.— Taken by Sig. Lediiion July 17. (No. i, 3) are craters No. i and 2. (No. 3 and 4) craters No. 3 and 4 in process orxformation. — (>«) Crater orm 

 vent at the north base of crater No. i.— (a)jMonte Nero about one km. west of the craters. • 



rent open, and I could observe from Acireale a dense 

 curtain of smoke rush up in great vortices, accompanied 

 by continual rumblings. Towards evening one could see 

 that the lava had advanced very rapidly in a southern 

 direction. At the upper part it was observable that 

 several jets, arranged in a linear manner, of fragment- 

 ary materials were being shot up to a great height, 

 especially at three main points on the new and great rift. 

 The explosive force of this eruption was much less than 

 that of the eruption of 1886, in which the fragmentary ejecta 

 were shot up to a height of 1200 metres, whilst in the pre- 

 sent case the height rarely exceeded 500 metres. This 

 fact depends on the great altitude and the great size of the 

 new fissure, which afforded a free escape for the energy 

 of the volcano, and gave forth a much greater quantity 

 of lava. The lava in less than three days travelled more 

 than four kilometres, and having surrounded Monte Nero, 



NO. I 197, VOL. 46 J 



candescent, divided by' deep depressions. It appeared 

 like the sea in a tempest, the waves of which in their 

 fury were suddenly petrified. From the crests were 

 constantly being detached fresh incandescent masses 

 which rolled down and choked the depressions, whilst 

 new gushes raised the masses of scoria into new hills of 

 fire. Amidst the phonolitic noise of the lava in move- 

 ment, I noticed gigantic puffings produced by the escape 

 of the vapour of H.,0, which, accumulating amidst the 

 mass of the lava, formed gigantic bubbles which rose and 

 burst, allowing the escape of the compressed gas. 



The eruption was very active during the following days 

 with short intervals of diminution or marked increase. 

 Remarkable phenomena were the blasts which shook the 

 doors and windows at Nicolosi, Acireale, and Catania, 

 and, at localities nearer the point of eruption, even the 

 walls. 



