The middle portion of the North Island is formed of an extended table-land, which towards its central point, that is to say, in the vicinity of the lake margin, attains to a mean altitude of nearly 2000 feet above the level of the sea. Beyond this radius, which I may term the inner circle of the great lake basin, the plane of elevation varies in altitude, and attains its highest point at its southern division, where, on the Onetapu desert, at the eastern base of the great mountain Ruapehu, it rises to a height of over 3000 feet, from which place it inclines gradually towards the south coast, and divides the northern and southern watershed of this portion of the country. Easterly of this the table-land is intersected by the Kaimanawa mountains, and from the western base of Ruapehu it falls with a rapid descent into the valley of the Whanganui. To the north of the lake, along the upper valley of the Waikato, it has an average elevation of from 1500 to nearly 2000 feet, until it descends into a broad valley near Atea-amuri, where the river flows round to the north-west to enter the plains of the lower valley of the Waikato. Eastward of the lake the highest point of the plateau is attained near to the northern slope of the Kaimanawa mountains, whence it dips in a north-easterly course, in the direction of the Bay of Plenty. Over a large area, along the western shore of the lake, the table-land maintains a more equal elevation than near the eastern shore-line, until it reaches the head of the Waihora river, whence it inclines north-westerly, around the high mountains of Titiraupenga, until it gradually merges into the broad, low valley of the Upper Waipa. It is as near as possible in the centre of this vast area of elevation, that the enormous sheet of water forming Lake Taupo is situated. The position of the lake is in lat. 38° 37' to 38° 58' S.; long. 175° 46' to 176° 5' E. Its mean altitude above the sea, by barometrical measurements, I ascertained to be 1175 feet. The margin, or shore-line, assumes a somewhat oval shape, with a broad bay on the western side. It is twenty-four miles long in a north-easterly and south-westerly direction, and fourteen miles broad from east to west, and with a superficial area of over 300 square miles. It possesses one small island, which is situated near to its south-eastern shore, and its coast is surrounded with beautiful bays and headlands, which in some instances rise many hundreds of feet above the white pumice shore. Although the waters of the lake are comparatively shallow around a greater part of the margin, there are places where it is of an enormous depth, especially near its centre in the direction of the western bay.