378 Transactions. — Geology. 



to me to be nearly of a circular form, and 500 feet or more in 

 diameter. It was quite impossible to descend to tbe lake, except 

 by the aid of a long rope, and even then the descent would be 

 attended with danger and difficulty. When I got on the top of 

 the peak I noticed little clouds of steam rising from the surface 

 of the water. On watching more closely, the water appeared 

 now and again to assume a rotatory movement, eddies and whirl- 

 pools passmg through it from the centre to the sides, and steam 

 flashing up from those eddies, leaving little doubt in my mind 

 that the water was in a boiling state. Close to the w^ater the 

 sides of the crater are bare of snow, and appear to be formed 

 of loose particles of rock and volcanic ash ; above are steep 

 inclines of snow, sloping in all directions towards the water and 

 terminating in icy masses overhanging the lake. The masses 

 of ice show, in the cracks and crevasses which intersect them, 

 and in their fringes of icicles, the effect which the heat from the 

 lake has on them. 



We had not very long been engaged in trigonometrical obser- 

 vations at the trig-station before a heavy cloud rolling up the 

 mountain side enveloped the peak and covered us almost in 

 darkness, so that we could not see one another ten yards dis- 

 tant. Whilst we sat on the mountain top waiting for this to 

 clear away and allow us to complete our observations, a portion 

 of the icy mass surrounding the lake, breaking away from its 

 position, crashed down over the precipice into the lake below, 

 sounding with an awful and solemn effect amongst the stillness 

 of all around. As the dense cloud continued to hang on the 

 peak, and the time had arrived for us to start back for camp, we 

 were obliged to leave our work for another day and commence 

 our descent. I may mention as a curious fact that on top of 

 one of the highest peaks of Euapehu we found, on a ledge of ice, 

 the remains of a rat in a good state of preservation, the skin 

 only being devoid of the fur, and a portion of it still remaining 

 on the chest, across which the fore-legs were folded. 



As I mentioned before, the snow-fields which fill up the 

 crateral hollows of the mountain prevent the possibility of 

 judging what the shape of the top is ; but from the vertical 

 inward faces of the peaks which can be seen, and the outward 

 appearances lower down the mountain on the western side, it 

 would seem reaoonable to infer that they surrounded a great 

 central hollow, and that the mountain had been a truncated 

 cone, large portions of the sides of which were blown away by 

 eruptions ; and that subsequently, inside the remains of the old 

 cone, two or more craters had broken out and built up new 

 cones. The vent in which the thermal action still continues 

 seems to be the last crater which was active, judging fi-om the 

 appearance of the lava streams down the mountain side. 

 Around the lower slopes of the momitain, and underneath some 



