i879-] 
The History of Vesuvius. 
463 
II. THE HISTORY OF VESUVIUS DURING 
THE LAST TEN YEARS. 
By G. F. Rodwell, F.R.A.S., F.C.S., 
Science Master in Marlborough College. 
S HE earlier eruptions of Vesuvius were of a violently 
paroxysmal character. The pent-up forces did not 
discharge themselves little by little at frequent inter- 
vals of time, but a long period of tranquillity, or of slight 
dynamic activity, was followed by one of great eruption. 
Prior to the eruption of A.D. 79 the mountain was not even 
regarded as an adtive volcano. From this period until the 
year 1139 there was no eruption of any magnitude, and then 
more than five hundred years elapsed before the mighty out- 
burst of 1631, which entirely changed both the shape of the 
mountain and the aspect of the surrounding country. From 
this time the eruptions occur more frequently. During the 
18th century the mountain was rarely in a state of rest, and 
more than four-fifths of the recorded eruptions occurred in 
this and the present century. These, as far as, and in- 
cluding the eruption of 1868, have been described so fully 
by Prof. Phillips in his admirable account of the mountain, 
that we need only refer to them, and may pass on at once to 
the history of Vesuvius since 1868. 
The eruption of 1868 terminated in November, and the 
mountain remained quiet till the end of December, 1870, 
with the exception of a few fumeroles of the crater, which 
emitted gases, and deposited near their mouths sublimations 
of chloride and sulphide of copper, and sulphide of potas- 
sium. Early in 1871 the seismograph of the Observatory 
showed signs of disturbance; slight detonations occurred 
within the crater, and incandescent particles were discharged 
in small quantity. On January 13th an aperture made its 
appearance on the northern side of the cone, from which a 
little lava issued, and around which a small cone was soon 
formed. A red-coloured smoke soon afterwards issued from 
it, and incandescent scoriae were ejected, while the detona- 
tions proceeding from the great crater were louder and more 
frequent. Lava continued to flow from the small cone, at 
short intervals, until the beginning of March, when the 
cone subsided, leaving a cavity about 30 feet in depth, the 
walls of which were covered with sublimations, while at 
