2 CORAL REEF AND ISLAND. 



pletely encircled the island, which was not a quar- 

 ter of a mile in diameter. Inside this regular ridge 

 were some scattered heaps of the same stuff, the 

 whole encircling a small sandy plain. The encir- 

 cling ridge was occupied by a belt of small trees, 

 while on the plain grew only a short scrubby vege- 

 tation, a foot or two in height. The materials of 

 the encircling ridge were quite low and thinly co- 

 vered with vegetable soil among the trees ; but the 

 sand of the central plain, which was dark brown, 

 was sufficiently compact to be taken up in lumps, 

 and a little underneath the surface it formed a kind 

 of soft stone, with imbedded fragments of coral. 

 Some vegetable soil also was found, a few inches in 

 thickness in some places, the result of the de- 

 composition of vegetable matter and birds' dung. 



On the lee or north-west side of the island was a 

 coral shoal or bank, sloping gradually off from low- 

 water mark for about a quarter of a mile, when it 

 was two or three fathoms under water. Imme- 

 diately beyond this was a depth of fifteen fathoms. 

 On the south-east, or weather side of the island, was 

 a coral reef about two miles in diameter, having the 

 form of a circle of breakers enclosing a shallow 

 lagoon. Among the breakers, on the external edge 

 of the reef, some large black rocks shewed them- 

 selves above water here and there all round. The 

 lagoon inside was shoal, having two or three fathoms 

 water occasionally over spaces of white sand, the 

 rest being occupied by flats of dead and living coral, 



