2.PRIL — sept. 1859.] the Province of Auckland. 151 



a South-westerly direction towards the Manukau, coming into con- 

 tact with the older and long-before hardened lava streams of " One 

 Tree Hill." The traveller on the Great South Road will observe 

 about one mile east of the Harp Inn" the peculiar difference in the 

 colour on the road, suddenly changing from red to black, where 

 the road leaves the older and more decomposed lava streams of One- 

 tree Hill and passes on to the new and undecomposed lava streams 

 of Mount Wellington. The farmers have been able to avail them- 

 selves of the decomposed lava surface, which is now beautifully 

 grass covered, but not of the stonefield of the newer Mount Welling- 

 ton and Mount Smart streams. 



The Caves at the " Three Kings," Pukaki, Mount Smart, Mount 

 Wellington, &c, are the result of great bubbles in the lava 

 streams — occasioned probably by the generation of gases and va- 

 pour as the hot mass rolled onward over marshy plains. These 

 bubbles broke down on their thinnest part — the roof — and the way 

 into the caves is always directly downward.* 4 ) 



Examples of every gradation may be seen — from the simple tuff- 

 crater without any cone, to those which are entirely rilled up by 

 the scoria cones. Especially interesting are those which maybe 

 said to represent the middle state, in which there is a small 

 cone standing like an island in a large tuff-crater, and surrounded 

 by either water or swamp. Perhaps the most perfect specimens of 

 this kind occur at Otahuhu and near Captain Haultain's, a map of 

 which, from actual measurement, has been prepared by Mr. W. Boul- 

 ton. You need not be alarmed when I tell you, that even the very spot 

 on which we are assembled is the centre of an old tuff-crater, from 

 which fiery streams once issued, and which has thrown out its 

 ashes towards the hill on which the barracks stand. — In order to 

 account for these various shapes, it must be borne in mind that 

 the cones of scoria where once higher, but on the cessation of 

 volcanic action they sunk down in cooling, and some entirely 

 disappeared. 



That the Auckland volcanoes were, in the true sense of the word, 

 "burning mountains," is proved not only by the lava-streams, 

 which are immense in comparison to the size of the cones, but also 

 from the pear-shaped volcanic bombs which, ejected from the 

 mountain in a fluid state, hove received their shape from their ro- 



