26 A NATURALIST IN THE PACIFIC CHAP. 



yards. It is even stated that as far as Ndaku, a mile to the west- 

 ward, the hot springs issue at intervals through the beach. 1 There 

 are evidently also extensive submarine springs close to the beach ; 

 and probably Wilkes was not far from the truth when he remarked 

 that the " whole area of half-a-mile square seems to be covered with 

 hot springs." 



Off the beach, a few hundred yards to the westward of the 

 springs, is a batch of dead reef formed of massive corals and only 

 approachable from the shore at extreme low-tide when it is a little 

 exposed. From numerous small holes and cracks in the dead-coral 

 hot water issues almost at the boiling point (210 F). It is apparent 

 that these springs have appeared at this particular spot since the 

 corals grew. But it is remarkable that this has been apparently 

 going on since the visit of Wilkes in 1840. He refers to a coral 

 rock, distant one-third of a mile from the springs and 150 feet from 

 the beach, through which boiling water was issuing in several 

 places. This rock which was then 10 feet wide and 20 feet long, 

 was at his visit exposed for three feet at low-tide and covered at 

 high-tide. 2 



The geological characters of this locality are described on page 

 191. I may here remark that if these thermal springs occupy the 

 position of an old crater, it would require much imaginative power 

 to restore it now. The off-lying small island of Nawi might by its 

 situation appear to countenance this idea, but I found no special 

 indication, when I examined it, in support of this view. From the 

 geological character of the district, I would infer that if a crater 

 once existed here it was submarine and that it has been long since 

 obliterated by marine and aerial denudation. The boiling springs 

 come up through apparently a rotten volcanic agglomerate. The 

 slight hollow of three or four feet deep, in which they lie, was 

 considered by Kleinschmidt to be an old crater cavity ; but it is 

 only 40 or 50 feet across, and in the earlier descriptions the hollow 

 is described as surrounded by a mound of earth. As shown below, 

 the natives themselves may be held responsible for many changes 



1 Pacific Islands, Sailing Directions, vol. ii., Central Groups, 1900, p. 185. 



2 From what I remember the usual exposure at low- water in 1898 was less 

 than a foot. I have little doubt as to the identity of the locality. This rock is 

 one of the " sights " of the place at the present time. It would be interesting 

 for a resident to compare carefully its present condition with that as described 

 by Wilkes. Dana in the work quoted on p. 10, refers to this rock as a knoll 

 of basalt ; but he never visited the locality and only obtained his account from 

 the officers of Wilkes. 



