Ch. II. 



BAERIEK EEEFS. 



65 



sent the form of the land from the shading of the hills 

 in the large published charts. It has long been 

 remarked, even from the time of Dampier, that a 

 considerable degree of relation subsists between the 

 inclination of that part of the land which is beneath 

 water and that above it : hence the dotted line in the 

 three sections is probably a moderately accurate repre- 

 sentation of the actual submarine prolongation of the 

 land. If we now look at the outer edge of the reef 



South. North. 



1 — Vanikoro, from the Atlas of the Voyage of the Astrolabe, by 

 D. D'Urville. 



2 — G-ambier Island, from Beechey. 



3 — Maurua, from the Atlas of the Voyage oi the Coquille, by Du- 

 perrey. 



The horizontal line is the level of the sea, from which on the right 

 hand a plummet descends, representing a depth of 200 fathoms, or 1,200 

 feet. The vertical shading shows the section of the land, and the hori- 

 zontal shading that of the encircling barrier-reef ; from the smallness 

 of the scale, the lagoon-channel could not be represented. 



A A — Outer edge' of the coral-reefs, where the sea breaks. 



B B — The shore of the encircled islands. 



