462 Mr Gardiner, The Coral Reefs of [Mar. 7, 



Vanua Vatu, a saucer-shaped island 1^ miles in diameter with 

 steep cliffs all round ; its height is 310 feet, and it appears 

 regularly table-topped from the sea 1 . Its reef fringes except to 

 the north- west, where it is of the barrier class. 



Naiau, Tuvutha, Mango, Vatu Vara and Naitamba have all 

 table-tops and the characteristic appearance of limestone islands ; 

 they are respectively 580, 800, 607, 1030 and 610 feet high. 

 Vatu Vara has merely one flat-topped peak, but the others are 

 typically round with central depressions about 200 feet below the 

 ridge. I was informed by Capt. Wilson and Mr Chalmers, a 

 former magistrate of Lau, that all are formed entirely of lime- 

 stone; this is confirmed by the survey 2 and very fully by their 

 appearance from the sea. In the interior of Mango nodules of 

 manganese are stated to be common, and, to drain it, a stream has 

 cut itself a passage to the outer side through the ridge. The 

 other islands are all said to have water holes in the centre, in 

 some of which the water is salt, though not below sea-level. 

 From the sea all appear to have very steeply sloping or pre- 

 cipitous cliffs, and I could see no trace anywhere of volcanic soil 

 or rock ; terraces are nowhere visible. The reefs usually are 

 fringing or very slightly barrier ; off Mango the reef has a few 

 low islets. Vatu Vara alone has a considerable stretch of low 

 lying land by the shore, rising gradually for 250 — 300 feet above 

 the sea and then precipitously for the last 700 feet ; southward its 

 hill ends in a cliff over 900 feet high. 



Thikombia-i-ra is, to judge from the descriptions I have 

 received and its appearance, certainly of limestone. Capt. Wilson 

 also told me that the rock is precisely the same as that of Fulanga, 

 and that at one of the chief landing-places a ladder is let down 

 through a hole in the overhanging cliff to ascend by. Its greatest 

 height is 680 feet, but it has several summits and no ridge ; its 

 hills at a distance appear to be very distinctly terraced. There is 

 no living reef of any sort except to the east-south-east, where a 

 barrier extends out for about 2 miles. The 100 fathom line lies, 

 however, about 13 miles beyond the reef, and there is a large 

 plateau 45 fathoms deep ; the edges in places are considerably less 

 deep, and it is in all probability an upgrowing barrier reef. 



Of the smaller islands in Lau, most are of the same hard 

 limestone, but a few low lying ones seemed to be formed of a 

 soft limestone, in all respects similar to the ordinary reef-rock. 

 Vatoa, I was informed, has both kinds of rock ; its reef is both 

 barrier and fringing, the former with in places a deep lagoon. 



1 Captain Wilson informed me that, near the landing place, the rock is much 

 indurated with large clam shells (Tridacna ?) 



2 Vide Sailing Directions for the Fiji Islands, 1882. 



