vI MOUNTAINS 241 
Perhaps the most destructive eruption of 
modern times has been that on Cosequina. 
For 25 miles it covered the ground with 
muddy water 16 feet in depth. The dust 
and ashes formed a dense cloud, extending 
over many miles, some of it being carried 20 
degrees to the west. The total mass ejected 
has been estimated at 60 milliaids of square 
yards. . 
Stromboli, in the Mediterranean (Fig. 23), 
though only 2500 feet in height, is very im- 
posing from its superb regularity, and its 
roots plunge below the surface to a depth of © 
4000 feet. 
It is, moreover, very interesting from the 
regularity of its action, which has a period 
of 5 minutes or a little less. On looking 
down into the crater one sees at a depth of 
say 300 feet a seething mass of red-hot lava; 
this gradually rises, and then explodes, throw- 
ing up a cloud of vapour and stones, after 
which it sinks again. So regular is it that 
the Volcano has been compared to a “flashing”’ 
lighthouse, and this wonderful process has 
been going on for ages. 
R 
