area, is covered with dismal-looking ponds of discoloured water, varying much in temperature, but in every case more or less saturated with sulphurous gases. Solfataras and mud volcanoes are also numerous, the pipes and crevices in the former being lined with crystals of sulphur. From Ohinemutu, I, in the first place, visited the geysers of Whakarewa, about two miles off, on the right bank of the Puheroa river. As compared with the small springs and fumaroles of Ohinemutu, those at Whakarewa exhibit, in much greater intensity, the effects of volcanic agency. Immediately across the ferry is a nearly circular Ngawha, or pond of boiling water, some twenty feet in diameter, the margin and interior surface of which are composed of silicious sinter, in the beautiful forms which this substance assumes in crystalization. The water of this Ngawha is of a rich mazarine blue, and as clear as crystal, and, when the steam happens to be blown gently from its surface, and the eye is thus enabled to penetrate the depths of the pond, huge masses of the same sinter, in the form of magnificent stalagmites and cascades, are seen to occupy the interior. The water of this Ngawha is rarely disturbed by ebullition, though a considerable rill constantly flows from it into the river. Beyond these are the two great geysers which form the principal feature at Whakarewa; and although I was not fortunate enough to see either of them in full play, I saw enough to afford some idea of the appearance which they would then present. Standing upon the edge of the crater of the smaller of the two, in which the water-pipe is about four feet in diameter, I saw the water gradually rise, with a roaring sound similar to that produced by the escape of steam from the discharge-pipe of a large ship, until it reached the lower surface of the basin. The ebullition then increased in intensity until the basin itself was nearly filled, and then a column of water, three or four feet in diameter, was frequently projected into the air to the height of twelve or fifteen feet, falling back into the basin in showers of steaming spray. The water then receded from the basin and slowly sunk to its former level in the pipe, where it remained in a state of ebullition, but, although I watched it for nearly half an hour, there was no repetition of the more violent effects. A still larger geyser lies in immediate vicinity to the one I have just described; but this had shown no signs of violent activity for some months, and is said to be very capricious in its action. I have little doubt, however, that long-continued and carefully-taken observations will establish as a fact (subject to the singular circumstance to which I shall hereafter refer), that the intermissions in the action of all these springs occur at regular intervals. Both of these greater geysers have formed, by deposit from their waters, rounded but irregular masses of silicious sinter, of a pure white colour and of very considerable extent, the pipes through which