NEW ZEALAND. 447 
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The volcanic region which has been thus briefly described, is very 
inferior in extent to that of the interior of the island, of which we have 
an excellent description by Dr. Dieffenbach. The lofty volcanic sum- 
mits of Egmont, Tongariro and Mount Edgecomb are evidence of what 
has been accomplished in former times on the island ; and this action 
is still going on, to some extent, at certain points in the line. White 
Island, farther north, in this line, is still smoking, and is said to afford 
abundant supplies of sulphur. Tahua, an island in the same bay, 
consists of rugged basalt and obsidian. On the coast near the 
Thames, between Waitemata and Manukao, there are numerous ex- 
tinct cones, many consisting of loose scoria. 
Mount Egmont abounds in cinders, slags and lavas, though, accord- 
ing to Dr. Dieffenbach, not active; its summit is a plain of snow 
about a square mile in extent. Tongariro stands near the centre of 
the island, about equally distant from the east and west coasts. Innu- 
merable boiling springs, solfataras and lakes are connected with it, 
and stretch along the northeast volcanic line. This crater, though 
still smoking, is not known by the natives to have been the scene of 
any recent great eruption, beside showers of ashes; it is described 
as an abyss a fourth of a mile in diameter. Lake ‘Taupo is the largest 
of the boiling springs of this neighbourhood: it measures thirty-six 
miles by twenty-five in breadth, and is twelve miles distant from ‘Ton- 
gariro, and thirteen hundred and thirty-seven feet above the level of 
the sea. Several streams flow into it from the snowy peak of Rua- 
pahu and other heights to the eastward. On the western shores 
vapours arise from a hundred crevices or pools having a temperature 
of 200° to 212° F., and subterranean noises are heard, like the work- 
ing of a steam engine. Near Lake Terapa, there are two square 
miles covered with springs of hot water; around the sides of some, 
siliceous sinter and magnesite are constantly forming ; and about one 
of them saucer-shaped aggregations of silica shoot up, compared by 
Dr. Dieffenbach to fungi. Deposits of chalcedony are also found, re- 
sembling flint in compactness. Some of the springs are strongly 
saline, while others contain sulphate of iron, and evolve sulphuretted 
hydrogen. On the river Waikate there are numerous steam-holes and 
hot springs, some of which have the power of petrifying wood. A 
part of Rotu Mahaina, or Warm Lake, imperfectly separated from the 
rest by a ledge of rocks, is in constant ebullition, and steam issues from 
countless openings among the foliage of the hills around. Siliceous 
deposits form numerous steps, one to two feet broad, which in texture 
