33% CENTRAL BAND OF TORRES STRAIT. 



narrow fringing reefs round the islands composed of 

 other materials. These are porphyries, granites, 

 and quartz rocks, and are an extension of the rocks 

 of the east coast of Australia across towards New 

 Guinea. None of these rocks are found in Murray 

 or Darnley, or any other islands to the eastward of 

 the line of reefs now referred to. This band, then, 

 running north from Cape York, across Torres Strait 

 towards New Guinea, forms a division between the 

 Great Barrier reef and any coral reefs which may 

 hereafter be found to the west or north-west of 

 Torres Strait. As far as our examination extended, 

 none such are to be found (except the very narrow 

 fringing reefs round the islands), but there are many 

 reefs laid down to the northward and westward in the 

 old charts, which have been cursorily seen by passing 

 navigators, and may be independent coral reefs. 



The Great Barrier reefs are thus found to form 

 a long submarine buttress, or curtain, along the 

 north-eastern coast of Australia, rising in general 

 precipitously from a very great depth, but resting 

 towards the north on the shoaler ground of Torres 

 Strait, and towards the south on the bank stretch- 

 ing off from Sandy Cape. If it were to be laid dry, 

 this great Barrier would be found to have a con- 

 siderable resemblance to a gigantic and irregular 

 fortification, a steep glacis crowned with a broken 

 parapet wall, and carried from one rising ground to 

 another. The tower-like bastions, of projecting and 

 detached reefs, would increase this resemblance. 



