THE RECENT REMARKABLE SUNSETS. 
183 
it to nearly 3000 feet above tlie sea; this volcano had long 
been dormant and its slopes were covered with woods; a period 
of two centuries having passed since it showed any volcanic 
action. In the present eruption more than half the island 
disappeared, a portion measuring three miles length by two 
miles average width having not only gone, but there is now 
a depth of nearly 1000 feet of water on the spot. At the 
same time two new islands have appeared, at eight miles dis¬ 
tance, one of them being where there was previously a depth 
of 150 feet of water; and the island to the west of Krakatoa 
has been more than doubled in size. 
This extraordinary disturbance of the surface of the earth 
caused a gigantic tidal wave which travelled from Krakatoa 
east and west completely round the earth; and from the 
numerous records of the tide gauges that have now come in 
from all parts of the w T orld it has been ascertained that these 
two waves met on the opposite side of the earth from Kraka¬ 
toa and did not vanish there, but crossing each other, 
journeyed on to their starting point, and actually then 
proceeded forward again as before and repeated their journey 
round the earth, performing this course, it is stated, no less 
than four times before the equilibrium of the sea was restored 
so far as to be insensible by the instruments of observation. 
This great wave transmitted through the water is now found, 
from the delicate barometrical registers in numerous parts of 
the world, to have had a parallel in the atmosphere, in an 
atmospheric wave also transmitted round the earth from this 
gigantic and unprecedented explosion. This atmospheric 
wave has been traced in its progress in both directions round 
the earth, and is found to have travelled with the same 
velocity as sound waves are transmitted through the air. 
There appears reason to suppose, from the enormous quantity 
of floating pumice that appeared at the time over a wide area 
of the sea, that the main eruption was a submarine explosion 
at some distance westward from Krakatoa, and that the 
Krakatoa eruption, gigantic as it was m extent, was really 
only a secondary symptom of a still greater Indian Ocean 
eruption. 
When there is taken into consideration the enormous ex¬ 
plosive force that must have been in action to produce such an 
effect as the bursting asunder and rooting up of a mass of 
the island of Krakatoa so large as three miles length and two 
miles width, leaving deep water in its place, and perhaps pro¬ 
jecting this mass to a distance of eight miles, where two new 
islands were found after the eruption;—the feasibility of the 
idea that has been suggested of minutely divided volcanic 
