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165 
As the eruptions of Vesuvius became more numerous they 
were less severe. Of recent outbursts that of 1872 is the most 
noted. On that occasion part of the town of Sebastiano was 
destroyed, and about 80 persons perished. Cinders fell at 
Naples, and so thick was the shower that the sky seemed 
hidden. 
Not unlike the first recorded eruption of Vesuvius was the 
sudden revelation of the nature of Mount Terawera, in New 
Zealand, in June of last year (1886). There was a range of 
mountains which, though known to geologists to show signs of 
past voleanic activity, were regarded as harmless. On the 
evening of June 9th earthquake shocks were felt, but it was 
not until half-an-hour after midnight that the shocks became 
alarming. At about ten minutes past 2 a.m. on the morning 
of 10th, a climax seems to have been reached; a most violent 
earthquake was experienced accompanied by a “loud roar,” 
caused by the outbreak of the voleano. This first earthquake, 
though severe around the centre of disturbance, was only 
slightly felt at 12 miles distant, and was, therefore, probably 
not deep seated. Shortly before 4 a.m. a second severe shock 
occurred, which was felt at a distance of between 60 and 70 
miles from the centre of disturbance, and was probably deep 
seated. The shock was followed by loud reports, and the out- 
bursts of immense volumes of steam which issued from the 
site of Rotomahana Lake. Large geysers rose from the site of 
the celebrated terraces, the largest of which came from the 
position of the Pink Terraces. The geysers threw up boiling 
water, mud and stones to a height of 600 to 800 feet. 
The volcanoes which I have referred to are fairly typical, 
but my reference to them has of necessity been brief, and I 
must now proceed to say something as to the cause of their 
formation and action. Many theories have been put forward, 
but so far the mystery has not beenclearedup. In considering 
the matter for ourselves we may start with the fact that the 
disturbance is due to changes which take place within the 
interior of the earth, though possibly not at excessive depths 
from the surface. Another fact which we notice is that large 
