142 Lectur* on the Geology of [No. 9, new series. 



to Kaipara. This extensive plateau is intersected by many deep 

 valleys, the sides of which are characterised by a succession of 

 remarkable terraces. The same plateau is also broken in many 

 places by more or less regular trachytic cones from 1000 to 3000 

 feet high. That you may become acquainted with the geological 

 character of such mountains, I will mention several examples, the 

 names of which are well known amongst European settlers. To 

 this class of mountains belong Karioi on the West Coast, near 

 Whaingaroa, Pirongia on the Waipa, the regular cone of Kake- 

 puku between the Waipa and Waikato, Maungatautari on the 

 Waikato, Aroha on the W aihou, Putauaki or Mount Edgecombe 

 on the East Coast, and many others. The only active mountain 

 which belongs to this class is Whakari or White Island, in the 

 Bay of Plenty, a solfatara like the active crater of Tongariro, 



(*Mr. David Burn, in his account of " A Trip to the East 

 Cape," says : — 



" In about an hour after passing Flat Island, the snowy vapour 

 upon White Island began to be discernible. By 1 p. m. we were 

 in immediate contiguity with this remarkable island, passing quite 

 close to its southern extremity. As we made our gradual ap- 

 proach, its aspect was of the most singular description. Except 

 on its northern point, to which the" sulphurous vapour does not 

 seem to reach, it is utterly destitute of vegetation; there are 

 patches of growing underwood ; but in every other direction, the 

 island is bald, bleak, and furrowed into countless deep-worn ra- 

 vines. After we had passed it a short distance to the eastward, 

 the capacious basin of the crater, with its numerous geysers roar- 

 ing and raging, exposed its sulphurous bosom to our eyes and 

 nostrils. If the outer and western sides of White Island be blank 

 and furrowed, its inner circle is chased, as it were, in a rare and 

 picturesque manner, — the sides of the hills, from their lofty moun- 

 tain summits to the base, being combed into innumerable longitu- 

 dinal ridges of a florescent bronze of brilliant and variegated hue." 



Of this island, Captain Drury, of H. M. S. " Pandora," gives 

 the following description in the " New Zealand Pilot :"— 



" White Island, or Whakari, is about three miles in circumfer- 

 ence, and 860 feet high. The base of the crater is one and a half 



