198 
^TNA AND VESUVIUS. 
From this time it rapidly diminished in size by 
the action of the waves, and on the 25th of August 
was only two miles in circumference, and on the 
Sd of September three fifths of a mile round and 
107 feet high, with a crater 780 feet in circumference. 
On the 29th of September its circumference was re- 
duced to about 700 yards, and was composed of in- 
coherent ejected matter, scoriae, pumice, &c., form- 
ing regular strata. Towards the close of October 
no vestige of the crater remained, and the island 
was nearly levelled with the surface of the ocean, 
except in one place, where there was a small sand- 
bank. At present there is a dangerous reef of vol- 
canic rocks, about ten feet under water, where the 
island formerly stood. 
JEtna. — The eruptions of ^Etna date back among 
the earliest records of history. The first on record 
is in the year 480 before Christ. This was foUawed 
by others, 427 and 396 B.C. Then, after a lapse 
of 250 years, we have four more, between 140 and 
122 B.C. Then, after 66 years of rest, we have three 
others, between 56 and 38 B.C. Seventy-eight 
years then elapse before another, in the year 40 
A.D. A pause till 251 A.D. Another till 812 A.D. 
A third to 1169 A.D. Since then, in the 12th and 
13th centuries, we have had 3 eruptions; in the 
14th, 2 ; in the 15th, 4 ; in the 16th, 3 ; in the 17th, 
8 ; in the 18th, 14 : in the 19th, 6 eruptions. The 
number of eruptions in Iceland during the last nine 
centuries is 42.* 
Vesuvius, — At the time of Strabo, Vesuvius offer- 
ed no other indications of its volcanic character than 
might be inferred from the analogy of its structure 
to other volcanoes. The ancient cone was of a very 
irregular form, terminating with a flattish summit, 
where the remains of an ancient crater, nearly filled 
up, had left a slight depression, covered in its exte- 
* Daubeny on Volcanoes. 
