Jounston-Lavis— The Eruption of Vesuvius in April, 1906. 149 
Fiechter * give the maximum height attained by the smoke pine in April as 
10,000 to 13,000 metres. No day is given, but I presume it was on the 8th. 
This column bent over in a north-east direction, continuing the destruction of 
Ottajano, S. Giuseppe, and the other towns in that direction. 
Great discrepancies exist between the different observers as to the cause of this 
bending over of the column of ejecta towards the north-east. De Lorenzo 
attributes it to the south-west wind ; but, as will be seen by the appended table, the 
wind at the Observatory of Capodimonte was absolutely in the opposite direction, 
and blowing at from 17 to 20 kilometres per hour. But of this we shall speak 
in the general discussion of the phenomena. During the day of the 8th a vast 
crater was excavated in the great cone of Vesuvius, half a kilometre in diameter, 
and probably extending far below the level of the Pedimentina. ‘The enormous 
mass of materials derived from this was spread over the slopes of the mountain, 
constituting at the base of the cone a gigantic accumulation of the larger masses 
that fell within short range of the volcanic axis, or that collected on the cone itself, 
and from time to time slipped to its base. During all the day of the 8th the 
whole mountain was enveloped in an impenetrable cloud of cocoa-coloured dust. 
Above this, at frequent intervals corresponding with land-slips of the crater-edges, 
followed by the expulsion of the loose materials, great pine or cauliflower-like 
masses rose above the general dust-cloud, of a darker and more leaden colour. 
This spread out, and was principally carried towards the north-east quadrant. 
In fact, in the morning most of the accessory lapilli and blocks were ejected, 
which, from the larger quantity and greater density, did the greatest damage 
to Ottajano and the neighbouring towns and villages. The fall of dust that 
had off and on continued in the province and town of Naples since the 4th 
became still more abundant and of the cocoa-colour of which we shall speak. 
The shocks and vibrations continued all day. Added to this was the thunder 
from the lightnings that played continuously in the dust-cloud. The violence of 
these noises was such that they were heard far and wide, reaching into the 
Puglias, and even ships in the Adriatic were enveloped in thin clouds of dust. 
Towards evening there was some diminution in the violence of the outbursts. It 
was, however, not till 10 p.m. or later that the lapilli-shower stopped at Ottajano. 
April 9th.—All through the night there was marked eruptive activity, but 
with progressive weakening in its violence. Nevertheless, the explosions were 
still audible in Naples till about 9 a.m. The bending over of the column of ejecta 
to the north-east had stopped during the night. The forces of explosion also were 
becoming exhausted, so that the materials that could be ejected became finer and 
finer. The north-east wind seemed to make headway, and carried these finer 
* “ Appunti sulla Eruzione Vesuyiana, 1905-1906.”—Bull. Soc. Geol. Ital., vol. xxy., 1906, p. 847. 
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