334 Transactions. — Geoloc/y. 



the 18th March, 1793. D'Entrecasteaux also gave the general 

 name to the group, calling it Kermadec, after the commander of 

 his consort. The name Sunday was given to it by Mr. Raven, 

 commanding the transport Britannia, who passed it in 1796 on 

 his way from Norfolk Island to Cape Horn. He was not aware 

 of its previous discovery by D'Entrecasteaux. The first settlers 

 took up their residence on Sunday Island in 1837, and from that 

 time to the present it has been occupied by various parties of 

 settlers, none of whom, however, ever stayed there any length 

 of time, owiug principally to causes which I shall refer to in the 

 geological description. 



Situated in latitude 29° 15' South, the climate is mild 

 and equable, although in winter high winds are of common 

 occurrence. The insular character, doubtless, tempers the 

 heat which might be expected froin the latitude. We found 

 the temperature, during our ten days' stay in August last, 

 very pleasant, and slightly higher than that of northern New 

 Zealand. 



The islands are wholly of volcanic origin, and are, geologi- 

 cally speaking, of recent date. I have attempted to show, in 

 the case of the Bay of Plenty volcanic district, that all the 

 extinct volcanoes there found, as well as the active ones, in- 

 cluding Tarawera and also the points of greatest thermal acti- 

 vity, follow a line drawm from Ruapehu to White Island, which, 

 there is every reason to believe, denotes one of those great 

 fissures of the earth so characteristic of volcanic districts. This 

 linear arrangement of volcanoes is so marked a feature as to 

 render it unnecessary to point out the many countries which 

 illustrate it. In the Kermadec Group, further evidence of the 

 ruling process by which volcanoes are built up along linear 

 fissures is afforded. If we study a map of the Southern Pacific, 

 we shall find that, by prolonging the volcanic axis of the Bay of 

 Plenty, it will strike through this group, and, if continued still 

 further in the same general direction, that Tonga and Samoa 

 will be seen to be in the same line. At both of these places 

 volcanic activity is still to be found, but more especially at the 

 former, where two notable eruptions have occurred within the 

 last few years — viz., that on the Culibras Beef, on the 11th 

 October, 1885, and that at Niuafou in August, 1886. 



This line appears to mark the centre of a region of elevation, 

 separated from similar ones on either side by oceans of abys- 

 mal depths. Unfortunately, the soundings between the coasts 

 of New Zealand and Tonga are few and far between. Tbe 

 < 'hallenger, one of whose special duties was that of deep-sea 

 sounding, only obtained four between the places named — i.e., one 

 off the East Cape, of 700 fathoms; two between Sunday and 

 Macaulay Islands, one 40 miles north of the former ; and one of 

 2,900 fathoms between Sunday Island and Tonga, but 150 miles 



