340 Transactions. — Geology. 



It is far different, however, at the bottom of the great crater 

 in the neighbourhood of the Green Lake. When the outburst 

 took place, the mass of ejected mud, pumice, and rock broke 

 away the encircling ring of hills, and poured down into the 

 larger lake, partly filling it, and for a time raised its waters 

 some 10 feet higher than it is at present, as may plainly be 

 seen by the blocks of pumice stranded some way back from 

 its margin. At the same time a great mass of mud and 

 fragments of rock were ejected in all directions from the little 

 crater, destroying the vegetation, some of it falling on the 

 southern side of the greater crater within which the Green Lake 

 lies, and there, in its descent, bringing down all the trees, and 

 leaving the cliffs bare, as they still are in some places at the 

 present day. The depth of this deposit is about 12 feet around 

 the rim of the crater, and through it are protruding the stumps 

 of the pohutukawa trees killed at the time of the outburst. 

 The last material to be ejected from the crater was pumice, in 

 blocks of all sizes from an inch to 2 feet in diameter ; and this 

 was apparently not cast out with sufficient force to overtop the 

 crater rim, for it is confined to a level bed rising about 10 feet 

 above the level of the water, and surrounds the lake as a raised 

 beach. Amongst the matter ejected are quite a number of 

 vomited masses of molten andesite, very like pitch-stone in 

 appearance, as large as small oranges. At the present time 

 steam at a temperature of 135° escapes from two or three 

 places within the crater rim, but no hot- water is found. There 

 is a somewhat singular cave on the east side, from the floor of 

 which the steam arises in sufficient quantities to make it 

 unpleasantly warm, and on the sides of which is deposited a 

 considerable amount of soft white matter not unlike gypsum. 



It is remarkable that there was a considerable fallmg-off in 

 the volume of steam from these places in the week following the 

 Tarawera eruption, as observed by the Bell family. Mr. Bell 

 assured me that the place is now not nearly so active as it was 

 prior to June, 188G, and this fact affords further evidence of the 

 connection between New Zealand and Tonga, along the fissure I 

 have attempted to describe. 



Tbe land surrounding the Green Lake presents a very desolate 

 appearance, covered as it is with bard mud, pumice, obsidian, 

 and fragments of andesite ; but the pohutukawa and Kermadec 

 ngaio are gradually gaining a hold on it, and in a tew years' 

 time will have obliterated all signs of tbe eruption. It is notice- 

 able that the stumps of the trees still protruding above the mud 

 arc nowhere of any size, thus probably indicating that the 

 eruption of 1872 was not the first one in that locality which was 

 sufficiently serious to destroy the vegetation. 



Although the eruption of 1872 is the latest which has occurred 

 on Sunday Island, a disturbance of much more recent date took 



