460 
THE GEOLOGY OE NEW ZEALAND. 
ness of more than a hundred feet, another convulsion up- 
heaves the whole, allows time for another growth of forest, 
when all again subsides, and the same process is repeated ; 
the traveller along the coast has only to read these pages of 
the Earth's history, which are unfolded for his instruction, 
and reflect upon them ; but this is only a page, and one 
which is visible : another remains still to be examined. 
The sure indications of coal, which further along the coast 
crops out, betoken a series of more ancient convulsions; 
modern subsidings of the earth's surface to such an extent 
are happily rare, although doubtless many have occurred 
in places where there were none to see or make them known,* 
to what is the present exemption from such terrible visita- 
tions in these islands to be attributed, but to the volcanoes 
which extend through them, they have poured forth their 
streams of molten rock, filled up the cracks and crevices of 
the earth's crust, strengthened the deficiencies of its frame- 
work, and thus we may hope, hindered the recurrence of 
future convulsions, small perhaps as is the extent of these 
islands now to what it formerly was, these streams of lava 
assist in stopping further encroachments on the land, thus 
while the ocean is rapidly gaining on some parts of the 
south-west coast of the Northern Island, the promontory 
of Cape Egmont presents its front to the surge, and with- 
stands its fury ; strengthened by numerous streams of lava, 
which are plainly seen like buttresses at every headland 
from that Cape as far as the Sugar-] oaf rocks, they form so 
many barriers to the sea's further inroads. That these 
islands have been disrupted by former convulsions, is seen 
by a single glance at the map ; but the period is, perhaps, 
as far back as the general disjunction of the continental line 
of which New Zealand is only a surviving link. 
A few words remain to be said of the rocks of New Zea- 
* The natives have several traditions of lands and islands having been sub- 
merged. There is one of an island near Taranaki, which had a very large 
Pa upon it suddenly sinking with all its inhabitants during the night ; of 
another at Patea, and of a great island in Cook’s Straits, called Titapua, thus 
disappearing. 
