MOUNT RUAPEHU.
In describing the physical and geological features of Ruapehu, I will only treat these subjects briefly at this stage, and only with a view of affording a general idea of the great mountain, the description of which will be more fully dealt with when describing the ascent of its northern peak and the exploration of the sources of the Wangaehu and Waikato Rivers on its eastern side. As during these two ascents we accomplished considerably over 10,000 feet of actual climbing over its surface, we had a good opportunity of examining this colossal monument of plutonic fires, and judging from the magnitude of the results of igneous action we then beheld, both in wonder and admiration, there can be no doubt that there is no better or more interesting field for geological research than that afforded by this marvellous centre of extinct volcanic forces.
Ruapehu is situated immediately in the centre of the great table-land which forms the most elevated portion of the North Island, and in the very heart, as it were, of the extensive system of extinct volcanic cones, which constitutes one of the most remarkable and interesting features of this division of the country. The mountain, which takes rank among the largest extinct volcanoes in the world, assumes the form of an enormous truncated cone, with a far-reaching base of oblong form, and which gradually narrows towards the summit, at which point the mountain is nearly a mile in length from its northern to its southern peak. Its base, if calculated from where it springs from the level plains, may be estimated at about sixty miles in circumference. At each end of the mountain are two colossal cone-shaped peaks, and between them the minor peaks rise up in fantastic shapes, which change in outline and assume varying proportions with almost magical effect, as the mountain is beheld from different points of view. In fact, it is the succession of magnificent scenery thus produced which forms one of the grandest features of this marvellous monument of volcanic forces. For the greater part, the country surrounding Ruapehu is entirely open, and consequently the grand mountain is seen to wonderful advantage as it towers majestically to the skies. Immediately to the north are the Tongariro and Waimarino Plains, to the east is the Rangipo Table-land, in the centre of which, and stretching down the sides of the huge mountain, is the Onetapu Desert—a vast expanse of scoria, covering some fifty square miles—while to the south are the Murimotu Plains. On its lower northern and eastern slopes the mountain gives life to a vegetation in all respects similar to that found on Tongariro, but on its southern and western sides a primeval forest, in which the trees are of colossal growth, creeps almost up to the edge of the snow-line. To really realize the magnitude of this mountain king of the North Island, one must stand on its summit and look down upon its scoria-strewn base, covering millions of acres, explore its deep, rugged gorges, and examine the stupendous deposits of trachytic lava which lie in a strata of enormous thickness upon its sides, or roll down like crystallized rivers of rock from the extinct craters of the mountain, now spreading over the plains, now rising above the surface of the ground in the form of enormous, crenated ridges, which look like the walls of embattled strongholds. There can be no doubt whatever that at some remote period Ruapehu must have formed the principal centre of volcanic action in the North Island. It is of course impossible to define at what period the enormous mountain began, or even terminated, its eruptive state; but I am of opinion, as suggested in a previous chapter, that it rose into being after the extinction and subsequent subsidence of the great crater-basin now occupied by Lake Taupo. Ruapehu, unlike Tongariro, is not a true scoria cone in the sense in which the latter mountain may be classed, but a gigantic crater of elevation, which during its volcanic outbursts sent forth showers of ashes and rivers of lava which spread themselves for miles around the base of the mountain, while the surrounding region over a vast area was upheaved by the elevatory force of the stupendous fires as they burst forth from the great volcanic vent now crowned with glaciers and perpetual snow.
SUMMIT OF RUAPEHU.
Whilst we were resting to give our half-starved horses a feed of tussock grass, I went out into the plains to sketch the great mountain, as from the position where we were it presented one of its most beautiful aspects. From this point it bore exactly ten degrees east of south, the altitude of the Mangatoetoe stream at the foot of the mountain where we were being 3450 feet above the level of the sea. We had selected this position from which to make the ascent as it was the best place to reach the great northern peak, which forms the highest point of Ruapehu. This grandly beautiful pinnacle, with its glittering mantle of snow sweeping down its sides, towered far up to the skies, its summit being crowned with what appeared to be an oblong mass of rock, which assumed, from the aspect from which we viewed it, a singular resemblance to what is known in heraldic science as the "cap of maintenance." This grand crown, placed dexterously by the hand of nature upon the very topmost summit of the great peak, was a remarkable and conspicuous object, and as its ice-bound sides glittered beneath the sun, it appeared as if set with gems. Right from the very top of this portion of the mountain, its precipitous sides and long, rolling slopes stretched down to the very foot of the plains, and it did not take us long to see that it would be impossible to make the ascent and descent from where we were in a single day. We therefore determined to ride our horses as far up the low spurs as we could, tether our animals in a convenient spot, carry our tent and other necessary equipage up to the snow-line, camp there for the night, and make the final ascent on the following day.
There was a small clump of forest growing a considerable distance up the scoria ridges, and as this was the only belt of vegetation of the kind on our track, we determined to direct our course to it, in the hope of finding water and a suitable camping-place for our horses. Our route now lay over low scoria ridges, which were intersected in every direction by winding, boulder-strewn gullies, which evidently during the wet season and the melting of the snows formed, with the deep creeks, the principal channels of the watershed of the mountain, as it distributed itself from the heights above over the low country. Upon the sides of these gullies, and clustering about the vast deposits of scoria, grew a luxuriant vegetation of dwarfed alpine shrubs, while wherever the sides of the gullies were obscured from the sun the thick white frost, which had wrapped the country in its icy mantle on the previous night, rose up from the ground in the form of thick icicles, from two to three inches in length. These icicles, like those which covered the Waihohonu Valley, were the most curious I had ever seen. They rose from the small, disintegrated scoria, which everywhere covered the ground, almost in the shape of a plant with a straight stem and a fringed top; and, while some stood alone, others were clustered together, forming a thick mass of ice. It seemed, indeed, as if the moisture which had literally saturated the ground during the heavy rains we had experienced had been drawn up to the surface by the frost by a kind of capillary attraction, which had produced these miniature plants of ice.
When we arrived at the small picturesque bush of towai-trees, we found that there was but little or no feed in its vicinity, so we only halted here for a short time to explore the surrounding country. On our right were the level plains and sinuous ridges over which we had ridden, while at some distance to our left an enormous lava ridge, like a ruined wall, cut off all further view to the south. We cut a couple of alpenstocks and a flagstaff, and next determined to take our horses still further up the mountain, to a a point where we could see the last sign of the dwarf vegetation, some of the plants of which we found our animals would eat, in default of anything better.