NOTES AND QUERIES. 



191 



trachytic lava, breccia, tuff, obsidian, and pumice-stone, which, flowing over 

 the bottom of the sea, formed an extensive submarine volcanic plateau. The 

 volcanic action continuing, the whole mass was upheaved above the level of 

 the sea, and new phenomena were developed. The eruptions going on in the 

 air uistead of under the sea, lofty cones of trachytic and phonoHthic lava, of 

 ashes and cinders, were gradually formed. These eruptions, breaking through 

 tlie original submarine layers of trachytic lava — breccia and tuff, raised them, 

 and left them as we now find them, forming a more or less regular belt round the 

 central cones, and having a slight inclination from the centre outwards. These 

 belts I shall have occasion to refer to under the name of " tuff-craters," or 

 " cones of tuffs," or " craters of elevation." In the course of time the vol- 

 canic action decreased, and we must now imagine that tremendous earthquakes 

 occurred ; that parts of the newly-formed crust gave way and fell in, forming 

 vast chasms and fissures, which are now occupied by the lakes, hot-springs, 

 and solfataras. 



Thus we now find in the central part of the Northern Island an extensive 

 volcanic plateau of an elevation of two thousand feet, from which rise two 

 gigantic mountains, Tongariro and Ruapahu. They are suiTounded by many 

 smaller cones, as Pihanga, Kakaramea, Kaharua, Rangitukua, Puke Onake, 

 Hauhanga. The natives have well named these latter, "the wives and 

 children of the the two giants Tongariro and Ruapahu ;" and they have a 

 legend to the effect that a third giant, named Taranaki, formerly stood near 

 these two, but quarrelliug with his companions about their wives, was worsted 

 in combat, and forced to fiy to the west coast, where he now stands ui solitary 

 grandeur, the magnificent snow capped beacon of Mount Egmont (eight 

 thousand two hundred and seventy feet). These are the three principal 

 trachytic cones of the Northern Island. 



By far the grandest and loftiest of the three is Ruapahu, whose truncated 

 cone, standing on a basis of about twenty-five miles in diameter, attains a 

 height of nine thousand to ten thousand feet above the level of the sea, about 

 three thousand feet of which is covered -^-ith glaciers and perpetual snow. 

 Ruapahu, like Taranaki, is extinct. Tongariro alone can be said to be active. 

 Dr. Hochstetter distinguished five craters on Tongariro, three of which are, to 

 a certain extent, active. Steam is always issuing from them, and the natives 

 state that from the principal crater, called Ngauruhoe, on the top of the highest 

 cone of eruption (seven thousand five hundred feet), occasional eruptions of 

 black ashes and dust take place, accompanied with loud subterranean noises. 

 It may be remarked that the shape of the cone is changing, the western side, 

 for instance, having, during the great earthquake at Wellington in 1854, 

 fallen in, so that the interior of the crater is now visible from the higher points 

 in the Tuhua district on the Upper Whanganui. The remarkable fact, that 

 snow does not rest upon som.e of the upper points of the Tongariro system, 

 while the lower ones are covered aU the winter through, shows that those parts 

 are of a high temperature. 



There is an interesting account of an ascent of the highest cone of eruption 

 by Mr. H. Dyson, communicated to the "New Zealander," 1851, by A. S. 

 Thomson, M.D. Mr. Dyson, in 1851, and Mr. Bidwell, in 1839, are the only 

 Europeans who have ascended the highest cone of Tongariro. 



The second active crater of the Tongariro system, at the top of a lower cone 

 north of Ngauruhoe, is called Ketetahi. According to the natives the first 

 eruption of this crater took place simultaneously with the Wellington earth- 

 quake of 1854. Erom Taupo lake Dr. Hochstetter saw large and dense 

 volumes of steam, larger than those from Ngauruhoe, emerging from the Kete- 

 tahi crater. The third active point on the Tongariro system is a great soKatara 

 on the north-western slope of the range. The hot sulphurous springs of that 



