872 Transactions. — Geology. 



Abt. XLV. — Notes on the Eruption of Tarawera Mountain and 

 Rotomahann, 10th June, 1886, as seen from Taheke, Lake 

 Rotoiti. 



By Major W. G. Mair. 



[Bead before the Auckland Institute, 26th July, 1886.] 



During the first week in June the weather was stormy, the wind 

 being N.E. to N.W. and W., with a moderate rainfall. On the 

 6th of the month the wind changed to South, and clear cold 

 weather set in. This continued to the morning of the 9th, 

 when the wind hauled back to West, blowing a stiff breeze, with 

 a cloudy sky. In the afternoon there were several sharp rain- 

 squalls, but the night set in fine, the moon bemg just in her 

 first quarter ; and an occultation of Mars, which occurred about 

 9 o'clock, was clearly seen. The wind at this time was light. 

 At about a quarter past 1 o'clock on the morning of the 10th I 

 was awakened by an earthquake. This was followed in a minute 

 or so by a much heavier shock, which aroused everyone in the 

 place; and then there succeeded, at intervals of about 50 sees., 

 a succession of vibrations, varying in character, some being 

 uniform undulatory movements, others sharp and irregular ; 

 while some resembled the striking of heavy blows upwards. 

 This state of things continued for half-an-hour. About 1.45 I 

 was startled by a steady roar, like that produced by a blast- 

 furnace, or a great waterfall. A friend in an adjoining room 

 called to me to look out of my window. My room was on the 

 east side of the house ; and upon looking out I saw that all that 

 side of the heavens was aglow, and there seemed to be a great 

 column of fire rising to a height of about 15 to 20 degrees, 

 while above it was a dense column of black smoke. Masses of 

 solid matter appeared to be hurled up, amid showers of both 

 ascending and descending sparks. At the same time there was 

 a marvellous electrical display, all the ordinary forms of lightning 

 were there playing, as it were, through the flame, the white 

 light showing conspicuously against the red. Over and on 

 either side of this there constantly flashed rounded masses of 

 dazzling white light, as if caused by the explosion of bombs, 

 and bayonets of sparks, which crackled like fireworks. My first 

 impression was that there was an eruption of the Tikitiri 

 Springs, 2^ miles distant ; but upon ascending a hill I made out 

 the "Whakapoungakau Eauge in the foreground, the trees on its 

 summit being distinctly visible ; and then I made out that the 

 seat of action was Wahanga, the northernmost peak of Tara- 

 wera Mountain, some 13 or 14 miles distant. There was very 

 little tremor of the earth at this stage. I went down to the 

 lake shore, but could not detect any disturbance there. A 



