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These springs are perhaps the most remarkable signs of thermal activity on Tongariro (Photo. No. 7). Thev lie mi the north side of the mountain at an elevation of 4,700 ft. Great quantities of steam from the boiling water hang about the place, but there is rarely, if ever, any true geyser action. Considered as boiling springs, however, they are perhaps the most remarkable in the whole thermal region, from them issue several streams of boiling water. These are all impregnated with ttulphurous μ-ases, which cause incrustations on the neighbouring nicks, and which oause them to weather and decay with extreme rapidity. Another interesting physioal feature of the area are the lakes Nga Puna a Tama. Two of these are of considerable size, being about half a mile across. They occupy the floors of two explosion craters, and there are two other small craters near them which contain a little water. The larger lakes are depressed nearly 200ft. below the encirlillg ridge of rocks. The walls are partly olid Hows and partly of sooriaoeous material thrown out when they wen- active. These craters are evidently connected with a rent which has split through the old crater-ring south-west of uiuhoe. ' Cussen called this veiy appropriately the " Rift" (10), and he also noted the white iieai- it with their wonderful columnar structure. (7.) Futdue op the Volcanoes. Ii will no doubt be asked whether paroxysmal eruptions such as described above are likely to occur again. It is difficult to answer this question satisfactorily. We know so little about the causes of volcanic action, and of the time taken by that action to build up huge cones, that we can form HO idea how long these periods of dormancy are. Ordinary volcanoes show long periods of rest, when their sides must have b%en covered with soil between periods of activity. Ruapehu m.-u lie passing through one of these periods, which may last for millions of years, but it seems probable that eventually this volcano will break out once more. Tongariro, on the other hand, is in a moribund condition, and after spasmodic fits of activity, more or less intense, will finally become absolutely extinct. (C.) SURFACE-FEATURES. [By R. Speight and the Authok.] The Tongariro National Park and tin; adjacent country consist of a central chain of mountains running about 27° east of north, and arising out of a plateau some 3,000 ft. in altitude and which slopes gradually to the north, south, east, and wist. The range .shows towards its centre a comparatively low opening, some 4,000 ft. in altitude. On the east this high plain averages about six miles in width, and is bounded by the Kaimaiiawa Mountains. To the west and south it merges into the broken and forest-clad country watered by the Wanganui and its tributaries. The general surface-feai uies of the park are thoso produced by frost and by steam erosion on the structures due to volcanic action. The higher levels of the mountains, being covered by snow in winter ami exposed to a strong sun in summer, show in consequence marked signs of disintegration through frost. The rocks are traversed by the natural joints due to contraction on cooling 'roni the molten condition, and so water penetrates far into their interior, and in winter subjects them to enormous disruptive force. The surface of the mountains is therefore covered with very great quantities of disintegrated matter which shows little sign of weathering. This amount is increased by the fragments of scoria and lapilli thrown out by the volcanoes, which lie loose on the surface or which are only partially consolidated by the pressure of overlying solid lava-Hows. A great deal of this has been produced by the latest eruptions, so that nearly the whole of the top and sides of Tongariro is covered by scoriaceous matter. The loose covering thus due to combined volcanic action and frost is moved continually to lower levels by snow-slips and the streams which flow down the mountain-sides. On the lower parts of the slopes there are wide areas covered with small fragments which have not yet weathered down into soil. The streams all transport great quantities of the loose-material and deposit it on the lower levels. On the oast especially the action of the high westerly winds sweeping the lighter material from the river-beds and from the slopes leads lo areas, more Or less extensive, of shifting sands. The most important of these is the Onetapu Desert, which lies to the south of the Mangatoeloenui, and is traversed by the Wangaehu and the Waikato. This is dealt with at some length further on. True sand-dunes appear in these desert tracts, and their fixing by plant-life is an interesting matter. The slopes of Tongariro are not nearly so barren as those of Ruapehu, a fact possibly to U referred to difference in composition of the later lava-flows. These are more basic in character, ami therefore have weathered to a richer soil. The rivers running from the mountains have cut deep gorges in many places. A strange feature of some is that after flowing in fairly open valleys they suddenly fake their course through narrow ravines— e.g., the Waihohonu. This suggests, that recent elevation of the land near the mountains, or a rapid lowering of a part of a country, especially near Lake Taupo, has given these Line increased power to cut down their beds. Earth-movements have undoubtedly exerted a marked effect on the course of the rivers, and, it seems probable, have caused the transfer of some of the streams running from the Kaimanawas from the Rangitikei basin to that of the Waikato. The Wangaehu may in course of time turn north to Lake Taupo, just at is seems verv likely the i southerly branch of the Waikato has done. This is rendered all the more probable by the drift matter brought down by the Wangaehu and deposited between Ruapehu and the Kaimanai The steep fall of the st renins towards (lie lake also tends to produce the same result. For the most part the watercourses are quite dry, though during the melting of the winter's snow, water will lie abundant enough and floods common. Such have led to many channels, both shallow and deep (arising abruptly for the most part), being cut in the loose material of the plateau, with the result that there is frequently quite a maze of dry and deep watercourses, which have usually very steep sides. Occasionally these watercourses — called locally " wash-out*. " — have flat beds, occupied by a scanty desert vegetation.