F 180 7 
WAMU. 
THE ERUPTION OF VESUVIUS IN APRIL, 1906. 
Bye lel, do JOUNSIMOMNAA WIS WLIO, IO. Oie 5 INKEHSh.  roer. 
Late Professor of Vulcanology in the Royal University of Naples. 
(Puates II.—XXIII., incuupine two Maps.) 
[COMMUNICATED BY PROF, GRENVILLE A. J. COLE, M.R.I.A., F.G.S. | 
{ Published, January 11, 1909.] 
SraTE OF VESUVIUS ANTERIOR TO THE NEw ERUPTION. 
We find that several severe paroxysms shook the flanks of the great Neapolitan 
yoleano during the nineteenth century, rivalling those of the preceding one. 
The most important of these paroxysms occurred in the years 1822, 1834, 1850, 
1855, 1858, 1861, and 1872, besides which a considerable number of minor ones 
are recorded. ‘The last important outburst preceding the one that we are about 
to consider was that of 1872, when extensive outpourings of lava took place, and 
a crater of some considerable size truncated the summit of the great cone. 
After a period of a year and nine months, in January, 1874, the volcano 
showed signs of revival of its exhausted energy after the great outburst. From 
thence onwards, Vesuvius continued to exhibit constant activity, though little 
replenishing of the crater seems to have started before 1876. Kruptive cone- 
building seems then to have gone on with some regularity, increasing the filling 
up of the 1872 crater, and helped by the frequent overflow of lava into the 
annulus between the cone of eruption and the old crater. In October, 1878, 
the lava began to overflow the lowest lip of the old crater edge and down the 
cone into the Atrio. In September, 1879, when I first made acquaintance 
with Vesuvius, most of the northern and much of the eastern and western crater- 
lips of 1872 were already overlapped by new lava, and a considerable lava-plain 
filled the old crater. Near the centre of this crater-plain of lava rose a rapidly 
growing cone of eruption. About 1880 this eruptive cone began to overtop 
TRANS. ROY. DUB. SOG., VOL. IX., PART VIII, 2A 
