96 REPORT—1850. 
vitutem fati venit. Quo ergo nobis permansura promittimus bona fortune, 
et felicitatem (cujus ex omnibus rebus humanis velocissima est levitas) habi- 
turam in aliquo pondus et moram credimus? Perpetua sibi omnia promit- 
tentibus in mentem non venit, id ipsum supra quod stamus stabile non esse. 
Neque enim Campaniz istud aut Achaiz, sed omnis soli vitium est, male 
coherere, et ex causis plurimis resolvi, et summa manere, partibus ruere.’”— 
Quest. Nat. lib. vi. 
3rd. There seems at present no sufficient ground for affirming 
that one portion of the earth’s duration has been more subject 
to their occurrence than another ; 
4th. Or that one portion of the earth’s crust has always been 
more subject to earthquakes than another. 
4th bis, But some portions of the earth’s crust appear to have 
sustained a sort of periodicity in their visitation by earthquakes 
—long periods of repose being followed by shorter, but still 
long periods of agitation. 
Thus Antioch affords perhaps the most remarkable instance, having for a 
long period been shaken nearly every year during the Roman empire, then 
having a period of repose of nearly 300 years, and then again becoming very 
subject to these convulsions. 
5th. But those portions of the earth’s surface which lie in or. 
around the great present lines or centres of volcanic action do 
appear at present to be most subject to earthquakes, 
6th. And earthquakes are most prevalent and most violent in 
some relation to the activity and intensity of the volcanic ac- 
tion, at these lines or centres, at given times. 
There appears to be beyond question the closest sympathy within all vol- 
canic areas (i.e. areas where active volcanoes are found and surrounded with 
formations due to their former and present action), between the activity of 
the voleanic vents and the shocks of earthquakes. 
Thus, in 1816, slight earthquakes at Scaccia in Sicily preluded the eleva- 
tion of the new island Julia. 
When Monte Nuovo was thrown up in 1538, on the day and night before 
above twenty shocks were felt, 
When Monte Rossi was formed by /Etua in 1669, and when the enormous 
fissure of twelve miles in length at once opened up the bowels of the volcano, 
an earthquake shook down Nicolosi and damaged Catania. The eruptions 
of 1811 and 1819 were also attended with earthquakes. 
In Iceland earthquakes*long preluded the great eruption of Skaptar Jokul, 
and reached their maximum violence on the day of the eruption, 11th of June, 
1783. 
At Lancerote in the Canaries, violent earthquakes preceded and followed 
the eruptions, near the shore, of 1824, Santorin in the Greek Archipelago, 
was separated from Therasia by an eruption in the year before Christ 236, 
which, according to Pliny, was attended with earthquakes ; and several more 
recent submarine eruptions, near it, have been also accompanied with earth- 
uakes. 
᾿ In ἃ word, every great eruption, in whatever part of the world it has been ob- 
served, aud whether from a volcanic vent on land, or formed beneath the sea, 
is accompanied by earthquake shocksof greater or less violence and duration. 
