342 Transactions. — Geology. 



of the island from the heach below. In other cases the lava 

 streams are seen to fill up crevasses and hollows in the under- 

 lying pumice, conforming to the undulations of its surface. 

 This lava appears to have been in a very liquid form, for it is 

 nowhere more than a few feet thick, and has run along slopes 

 which have a very gentle inclination. Following the lava was 

 an ejection of black and dark-brown vesicular scoria, very much 

 like in outward appearance that seen in any of the cones around 

 Auckland, but differing somewhat from it. The presence of 

 olivine crystals in it shows, however, that the scoria is basaltic. 

 The scoria is deposited much deeper around the little crater 

 from which it emanated, and thins off from there towards the 

 eastern and lower parts of the island, being perhaps 100 feet 

 deep near the crater, and 2 to 4 feet on the lower ground. 

 Finally, following the scoria, an eruption of mud or fine ash 

 of a dark-brown colour took place, and this forms the not 

 unfertile soil of the island ; it is about 4 feet deep. 



To the east of Macaulay Island, and separated from it by a 

 narrow passage is Haszard Islet, which is formed of the same 

 lava and tuff as the larger island, but the scoria has not extended 

 so far. But here the inclination of the beds is in the opposite 

 direction, denoting that a partial subsidence has taken place 

 along the line occupied by the passage, which is probably a 

 fault. Viewed from any direction, Macaulay Island presents a 

 pleasant appearance ; the gentle undulations of the surface, 

 covered as they are with a close sward of green grass, would 

 form an attractive feature to the agriculturist were the island 

 situated near our own coast. Landing on its rock-bound shores 

 is very difficult, except in one place, and with favourable 

 weather, under the shelter of Haszard Islet, where a little sandy 

 bay is found. 



It is doubtful whether there is permanent water to be found ; 

 we saw none but a little in some rocky pools, and that was after 

 a recent heavy rain. 



Twenty-two miles south of Macaulay Island are the Curtis 

 Islands, separated from one another by a deep channel a quarter 

 of a mile wide. 



The eastern island is much tbe largest and most interesting 

 of the two, for here we have a crater much more active than 

 those on the other islands ; though this is hi what is called the 

 solfatara stage. The island appears to be formed of massive 

 lava, standing up out of the sea in perpendicular or overhanging 

 cliffs for a height of 500 feet. The crater is situated on the 

 north side, and is formed by a deep hollow in the massive rocks, 

 with almost perpendicular sides all round, excepting on the 

 north, where the sea enters by a little cove, the only landing- 

 place on the island. The floor of the crater is about 15 feet 

 above the sea-level, and scattered over its surface are a number 



