13S Lecture on the Geology of [No. 9, new «erie§. 



met with the following interesting account of an ascent of the 

 highest cone of eruption by Mr. H. Dyson, which was communicat- 

 ed to the New Zealander by A. S. Thomson, M. D. : — 



Mr. Dyson's Account of his Ascent of Tongariro. 

 In the month of March, 1851, a little before sunrise I commen- 

 ced my ascent alone, from the north-western side of the Rotoaire 

 lake. I crossed the plain and ascended the space to the North- 

 ward of the Whanganui river. Here I got into a valley covered 

 with large blocks of scoriae, which made my progress very difficult. 

 At the bottom of the valley, runs the Whanganui river. After 

 crossing the river, which at this place was then not more than a 

 yard broad, I had to ascend the other side of the valley, which, 

 from the unequal nature of the ground, was very tedious, and I 

 kept onwards as straight as I could for the top of the mountain. At 

 last I came to the base of the cone, around which there were large 

 blocks of scoria which had evidently been vomited out of the crater, 

 and had rolled down the cone. The most formidable part of my 

 journey lay yet before me, namely the ascent of the cone, and it 

 appeared to me from the position where I stood that it composed 

 nearly one-fourth of the total height of the mountain. I cannot 

 say at what angle the cone lies, but I had to crawl up a consider- 

 able portion of it on my hands and feet, and as it is covered with 

 loose cinders and ashes, I often slid down again several feet. 

 There was no snow on the cone or the mountain, unless in some 

 crevices to which the sun's rays did not penetrate. There was not 

 on the cone any vegetation, not even the long wiry grass which 

 grows in scanty patches up to the very base of the cone. The as- 

 cent of the cone took me, I should think, four hours at least ; but 

 as I had no watch, it is possible from the laborious occupation I 

 was at, that the ascent of the cone looked longer than it was. 

 But whether it was three hours or four that I was clambering up 

 the cone, I recollect I hailed with delight the mouth of the great 

 chimney up which I had been toiling. The sun had just begun 

 to dip, and I thought it might be about 1 p. m., so that I had 

 ascended the mountain from the Rotoaire lake in about eight 

 hours. I must confess as I had scarcely any food with me that I 

 kept pushing on at a good pace. On the top of Tongariro I ex- 



