SUMATRA 
161 
loose from its prison-house, dissipated itself into the air. 
The wave circles died away on the margin of the lake, 
which resumed its burnished face, and again reflected 
the blue sky, and silence reigned again until the geyser 
had gathered force for another expiration.Thus 
all day long the lake was swallowed up and vomited 
forth once in every fifteen or twenty minutes.” 
The most important mountain in the Lampong district 
is Tangkamus, better known to the Dutch as Keizers 
Spits, which dominates the head of Samangka Bay, and 
is estimated to be 7422 feet in height. The peaks at 
the extreme end of the island are of no great height. 
All the mountains we have mentioned are volcanoes, 
whether extinct or active, as are probably almost all in 
Sumatra. Their number has been estimated at sixty-six, 
but so much of the interior remains unexplored that 
these figures can only be approximate. 
Of all the volcanic eruptions known to have occurred, 
either in ancient or modern times, that of the island of 
Krakatau, in the Sunda Straits, which will be fresh in the 
mind of every reader, was at once the most stupendous, the 
most wide-spread in its effects, and the most destructive 
of human life. As far as regards the actual amount of 
matter ejected, and the area and duration of the darkness 
caused by the volcanic dust, other eruptions have 
exceeded it, as for example that of Tambora, in Sumbawa, 
in 1815, and of the Skaptar Jokull, in Iceland, in 1783. 
But in the suddenness and violence of the explosions, 
and in the disastrous effect of the resulting “ seismic wave,” 
it is without an equal. By this great eruption the volcano 
was completely eviscerated. A mass of matter, of not 
less than 1-|- cubic mile in size, was blown into the air 
in the course of a few hours, and nearly 40,000 people 
perished. 
M 
