Hector. — Presidential Address. 465 



Tarawera Mountain, he continued, stood a little way back 

 from Rotonaahana, and consists of three tops — Wahanga, 

 separated from the others by a deep chasm, and two others, 

 Ruawahia and Tarawera proper ; but he could not say how the 

 latter came to have separate names. It was at the south foot 

 of Tarawera that Rotomahana was situated, and around this 

 lake a continual outpouring of boiling water was going on, 

 throwing up huge geysers ; and enormous deposits had been 

 accumulating round the lake of siliceous matter, which com- 

 pletely sealed any escape other than the immediate geyser vents. 

 He had already stated to the Society many years ago that all 

 these terraces seemed to have the power of building up to about 

 70 feet ; and he recommended it to engineers to think that 

 question out, and see whether any relation can be established 

 between the temperature and an hydraulic head of 70 feet. 

 This was very obvious at Whakarewarewa. The result remains 

 that this action ended in cementing over the surface with 70 

 feet of hard and heavy siliceous rock. The continual out- 

 pouring of this matter from beneath, and the continual action 

 of hot water on the rock, must have absorbed a great deal of 

 heat. That heat was really derived from a remnant of the un- 

 cooled lava in the core of the Tarawera Range. 



On the 9th of this month (June) we had very stormy weather, 

 and on that day there set in all over this country a complete 

 change of weather. For nine months previous, he had been 

 informed, they had hardly had a shower of rain in the Tarawera 

 District; but on the 9th down came an enormous flood of rain, 

 and a change set in to very wet and cold weather. Another 

 circumstance deserves attention. This year we had had a most 

 unusual arrangement of atmospheric pressure in the Southern 

 Hemisphere. When passing the Equator, on the whole, baro- 

 metric pressure gradually declines towards the poles. It declines 

 much more rapidly towards the South than towards the North 

 Pole, so that while the barometer averages over 30 at the Equa- 

 tor, in New Zealand it is about 29'8, and a very little way 

 south the usual reading is only 29-2 or 29-3. But for some 

 reason an area of high pressure is generally situated to theN.E., 

 which this year has passed down much nearer to the South Pole. 

 When at the Antipodes Islands, in March, Captain Fairchild 

 found the unprecedented high reading of 30-8, the barometer 

 being in perfectly good order. In consequence of that, there 

 had been a great deal of continued easterly weather in New 

 Zealand. In any case, there were exceptional conditions of 

 weather and atmospheric pressure ; and, in connection with 

 this, he mentioned that a difference of an inch in the barometer 

 meant a difference of pressure of nearly one million tons to the 

 square mile. 



The earliest trace that he had been able to discover of any 



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