TRANSACTIONS OF SECTION C. 171 



ice-field showed that there ■svas a gradual movement of ice 

 towards the lake. Whether the size of the lake varies or not 

 I could not say; but according to Mr. Park's account of what 

 he saw from Paraetetaitonga Peak in January, 1886, the lake 

 must undergo some curious changes. On page 71 of the 

 "Eeports of Geological Explorations," issued under the au- 

 thority of Sir James Hector, Mr. Park reports, "At the time 

 of my visit the centre or, rather, the most depressed part of the 

 crater was occupied by a smooth sheet of ice of a greenish- 

 blue colour, which in alpine regions is generally considered 

 characteristic of ice-fields of great depth and permanence." I 

 cannot think, however, that Mr. Park could have seen the 

 position of the crater-lake now described, but that from liis 

 vantage-point he simply saw the ice-field between Te Heuheu 

 and Euapehu, for it is impossible to suppose that the lake 

 could have been frozen over, as the walls of the crater for 

 several hundred yards are simply in the condition of a solfatara. 

 In March, 1881, the lake as seen by Messrs. Birch and 

 Eussell was thought to be warm, as they distinctly saw steam 

 rising from its surface by aid of a good glass ; and Mr. Cussen, 

 as related by him on page 377 of " Transactions of the New 

 Zealand Institute," Vol. xix., clistinctly noticed " clouds of 

 steam rising from the surface of the water," and from the ap- 

 pearance presented he had little doubt that the water was in a 

 boiling state. Mr. Cussen ascended to the south peak of the 

 mountain three months after Mr. Park, and he estimates the 

 lake to be 500ft. or more in diameter, whilst Mr. Birch who 

 sav/ it in 1881 estimates the diameter at from 600 to 700 

 yards. Mr. Birch passed across the ice-field under the Peaks 

 Euapehu and Paraetetaitonga, and had a full view of the lake 

 from the west and south. His estimate of the size of the 

 crater more nearly corresponds to the size as it appeared in 

 March last ; but it may be that the ice-wall from the west and 

 south at times is pushed far across the lake, so that to an 

 observer on the east side of Paraetetaitonga the crater-lake 

 would hardly be seen. Eegarding the explosion which was 

 reported to have taken place in August, 1889, there can be no 

 doubt whatever that the water from the crater had welled over 

 the lip of the crater at a recent date, as the mark of its rise 

 had been left on the snow exactly in the same way as the 

 waves of the sea leave a ripple-mark on the shore. No la,rge 

 quantity of snow appears to have fallen between the date of 

 the eruption and my visit, and the debris and boulders of blue 

 clay were scattered over the ice, and could be traced on the 

 snow-field for about 50 yards from the crater walls. The 

 material that had been ejected was a blue-clay mud, re- 

 sembling the blue clay thrown out at Eotomahana during the 

 eruption in 1886. It is impossible to say whether the crater 



