276 CORALS AND CORAL ISLANDS. 
pelago is accordingly a vast island cemetery, where each 
atoll marks the site of a buried island; and the whole Pacific 
is scattered over with these simple memorials. 
In view of the facts that have been presented, it is fur- 
ther evident that a barrier reef indicates approximately the 
former limits of the land enclosed. The Exploring Isles 
(Feejee chart), instead of having an area of only siz square 
miles. the whole extent of the existing land, once covered 
three hundred square miles; and the outline of the former 
land is indicated by the course of the enclosing reef. A still 
greater extent may be justly inferred. For since a barrier, 
as subsidence goes on, gradually contracts its area, owing to 
the fact that the sea bears a great part of the material 
inward over the reefs, the declivity forming the outer limit 
of the sub-marine coral formation has a steep angle of in- 
clination. In the same manner it follows that the island 
Nanuku, instead of one square mile, extended once over two 
hundred square miles, or had two hundred times the present 
area of high land. Bacon’s Isles once formed a large trian- 
gular island of equal extent, though now but two points of 
rock remain above the water. 
The two large islands in the western part of the group 
Vanua Levu and Viti Levu, have distant barriers on the 
western side. Off the north point of the former island, the 
reef begins to diverge from the coast. and stretches off from 
the shores till it is twenty and twenty-five miles distant ; 
then, after a narrow interruption, without soundings, the 
Asaua islands commence in the same line, and sweep around 
to the reef which unites with the south side of Viti Levu; 
and, tracing the reef along the south and east shores, we find 
it at last nearly connecting with a reef extending southward 
from Vanua Levu. Thus these two large islands are nearly 

