502 REPORT—1883. 
as enormous fissures opening, from which large volumes of vapour were issuing, and 
similar statements. ‘he fissures were such as exist along the edge of all landslips, 
and the vapour which escaped, for only a few hours after, was nothing more than due 
to the sudden exposure ofa large surface of hot and moist muddy tufa, which formed 
the fumarole walls. The author visited with diligence, guided by the informers, 
the different localities where these natural wonders were to be seen, to be repaid by 
useless climbs beneath a broiling August sun. As he knew the island of Ischia step 
by step before the last catastrophe, so far as his observations go, he could find no 
change either in the level of any locality, or in the fumaroles or mineral waters. 
It may be remarked that this is said in the face of many statements to the con- 
trary, to the effect that some of the thermal waters boiled, or rushed out ‘in great 
quantity. Now there are many persons thoroughly worthy of belief who assert 
such to have been the case; but there are others quite as worthy of belief who deny 
it. Amongst some assertions, one was that the wells dried up; but in two 
cases at least the wells turned out to be underground cisterns for rain water, so 
that how the earthquake dried up these, other than by fracturing them, the author 
cannot conceive. 
Hardly any cliff edge but either slipped away or was fissured parallel to its 
borders; roads that ran along a declivity had either slipped down bodily into the 
valley, or were divided by fissures parallel to their axis. 
One fact, however, of which there can exist not the slightest doubt, is possibly 
an important discovery made by Dr. Eisig, trained to scientific observation, and: 
Mr. Petersen, the vice-director and engineer respectively of the zoological station 
at Naples. These gentlemen, when on a dredging excursion, with the aquarium 
yacht, a short time after the earthquake, noticed on the north of the island (@.e. 
opposite Casamicciola and Lacco) a number of pieces of fresh-looking pumice floating 
on the water. The conclusion was that there had been a submarine eruption. 
Thus would be explained the sensation of a blow struck at the two steamers at 
anchor in the roads at the moment of the shock, besides that against a boat three 
miles from the Punta Imperatore. 
Against such supposition there are mavy facts. (1) No one saw the eruption. 
(2) Supposing it to have passed unobserved in the night, surely the next morning 
there would still have been some very considerable escape of eruptive materials, 
especially when we remember the small depth between the island and the mainland. 
(3) We should expect a larger amount of pumice than was really found. (4) It 
is hardly compatible that a mesoseismal area occurred within the island, whilst an 
eruption occurred a small distance away, unless this were on the continuation of 
the fissure, and therefore opposite Lacco. (5) The presence of floating pumice 
might be explained by the landslips of loose tufa, containing that material, that 
ire sea cliffs in the immediate neighbourhood, and out of which it may have 
oated. 
It is, however, to be hoped that, as the zoological station possesses dredges and 
diving apparatus, they will divert their attention for a day or two to the investiga- 
tion of an important phenomenon, if such really exists. 
Fontana, as on the occasion of March 4, 1881, again showed a set of injuries 
dependent on a vertical shock. This time, however, the damage was much more 
strongly marked, and many houses were rendered quite uninhabitable, besides some 
that fell. In addition to the vertical injuries were a set of fractures denoting a wave- 
path, coming from the north at a very low angle of emergence. ‘The explanation 
proposed for the peculiarity of the injuries in this locality for 1881, seems to be 
confirmed ; the vertical seems to be due, as then, to the conduction along a column 
of trachyte followed by the direct shock from Casamenella, which produced the 
second set of fissures. An additional confirmation of this is, that at the convent 
of St. Nicola hardly any signs of vertical movement are evident, whilst objects on 
the altar gave a distinct north and south azimuth. 
The author examined the whole of the coast of the island, but could find no ap- 
parent change of level. A rough examination of the azimuths proves them to be very 
regular except near the mass of trachyte of Zale, which seems to have reflected the 
shock, so that the buildings in the neighbourhood of it, and especially on its 
