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HARDWICKE'S SCIEN CE-GO SSIP. 



old feeders of lava-streams. That the modern cone 

 of Vesuvius is one formed merely by eruption 

 admits of no doubt whatever. In the eruption of 

 79 no lava seems to have been emitted, at least 

 none is recorded, and the immense quantities of 

 ashes, sufficient completely to bury and hide away 

 cities for many centuries, have very much the 

 aspect of the tuff-beds of the Phlegrsean Eields. 



The earlier records of the state of Vesuvius are 

 necessarily very imperfect, nevertheless a rough 

 history of the mountain, from a.d. 79, forvrards, 

 has been made out. Prom this it appears that the 

 next grand eruption occurred in 1631 ; in the 

 previous centuries eruptions are chronicled as 

 having taken place from time to time, with con- 

 siderable intervals between, but none of any 

 magnitude, and Braccini describes the crater in tlie 

 17th century as overgrown with trees and shrubs 

 and the abode of wild boars. The eruption of 1631 

 gave vent to several large streanr.s of lava (green 

 lines on map) which overwhelmed in a great measure 

 Torre del Greco, Ptcsina, and Portici, killing 

 18,000 persons; while the immense columns of 

 vapoar and ash spread terror and destruction on 

 every side. 



Prom this time forwards the eruptions have been 

 numerous and severe, keeping the inhabitants of 

 the sea-coasts below in a state of continual excite- 

 ment. That of 1779 was very remarkable, on 

 account of a vast column of liquid fire shot up fully 

 10,000 ft., shedding a most brilliant light for miles 

 around ; and the ashes fell in such quantities as to 

 threaten the speedy burial of many neighbouring 

 towns, and were spread throughout a distance of 

 100 miles. 



A fourth grand eruption occurred in 1794, when 

 a fissure some 3,000 ft. long was produced on the 

 western flank of the mountain, and a series of small 

 cones, from which proceeded lava-streams that 

 overwhelmed great part of Torre del Greco and 

 entered the sea. Great discharges of vapour and 

 ashes followed, which deluged that country with 

 volcanic mud. ; 



The years 1822 and 1831 were signalized by 

 powerful eruptions, that of the former producing 

 large streams of lava flowing towards Resina, Torre 

 del Greco, and Bosco Reale, and being accompanied 

 by great quantities of grey and black ash ; that of 

 the latter giving rise to a wide current, which 

 destroyed 496 .houses out of 500 in the village of 

 Caposecchi. 



In 1850 the crater-walls were broken down, and 

 lava flowed southwards and enveloped Bosco Reale. 



In 1855, from a fissure on the north side of the 

 cone, proceeded a stream of lava of great fluidity, 

 which, passing on the north side of the ridge of Salva- 

 tore, reached very nearly to La Cercola, while a narrow 

 branch ran off towards S. Giorgio. Prom three 

 little craters in the north side of the cone, lava was 



ejected in 1858, some of which, after flowing first 

 into the Atrio del Cavallo, then turned towards the 

 Hermitage, and a large stream ran towards Resina. 



In 1861 eleven little cones were produced only 

 700 yards behind Torre del Greco, clouds of ashes 

 and great earthquakes accompanying their pro- 

 duction. 



In 1867 short currents flowed to the south-east 

 and towards the Hermitage, while in 1868 a stream 

 flowed to the north of the Salvatore ridge, threaten- 

 ing Massa di Somma. The eruption of the past 

 year is so fresh in the memory of all, that no details 

 are called for here. 



On ascending the mountain from Resina,* after 

 having passed through the vineyards clothing the 

 lower slopes, the great uneven current of 1858 is 

 encountered, a rolling sea of black lava with many 

 a cavernous hollow. What, however, most strikes 

 one is its ropy structure, many parts looking as if 

 innumerable coils of tarred rope had been thrown 

 in different directions. The curve of the ropy 

 masses indicates the direction of the flow. The 

 upper surface is completely vesicular and slag- 

 like, but the inner parts are hard and compact. 



After a passage for some time over this 1858 lava, 

 the ridge of San Salvatore is reached. Here stand 

 the Hermitage and the modern Observatory, upon 

 a green grassy island amidst a sea of encircling 

 black and rugged lava. Here, too, may be seen old • 

 ash-beds very similar to those of the Phlegr£ean 

 Pields, and probably of the age of the destruction of 

 Pompeii. Immediately to the south of the ridge 

 is the mass of twisted and tarred ropes and ruptured 

 blocks just passed over; to the north are seen the 

 currents 1855 and 1868, presenting for the most part 

 quite a different appearance, having but little of the 

 ropy structure and more the semblance of an accumu- 

 lation of loose blocks from a foundry, the surface 

 lava having evidently rolled over itself in a hurly- 

 burly fashion. This difference of surface-structure 

 is connected with the relative rates of flowing of 

 the streams. The current of 1855 may be traced 

 down the great valley just north of the ridge, 

 to where it forked, one branch running nearly to La 

 Cei-cola, the other towards S. Giorgio. 



On leaving the Salvatore, a section should be 

 noticed of one of the old lava-beds of Somma with 

 overlying ashes, this being in the line of the old 

 crater-walls destroyed along the western side in the 

 eruption of 79. Close by is the current of J 867, 

 with a rugged blocky structure at the surface. A 

 further walk of half an hour brings us fairly into 

 the Atrio del Cavallo, the valley separating the 

 modern cone of Vesuvius from the ancient Somma. 

 The structure of the cliffs of Somma may here be 

 well seen, beds of lava and ash dipping outwards 

 and cut through by numerous dykes, some per- 



* My ascent was made in May, 18/0. 



