346 HYPOTHESIS EXPLAINS PHENOMENA. 



the coast, but only shift its situation. It would be 

 thrown so much further forward, or towards the 

 east. Now suppose the coast cleared of coral reef, 

 and raised so much that it emerged from the sea 

 just within the line of the present Barrier reef. 

 Then let the reef commence in the shallow water 

 along that shore, and a very slow and gradual de- 

 pression take place, giving time for the polyps to 

 build up so as to keep near the surface of the water. 

 The result of this action would be the present Bar- 

 rier with its steep outer slope, and its gradual exten- 

 sion over the sinking rocks that were once dry land 

 within it. Portions that were once hills on the 

 dry land would now be islands between the Barrier 

 and the main, such as Sir C. Hardy's Island and 

 those about it. Islands that once existed in front 

 of the main land would now be altogether sub- 

 merged, and their places only marked by detached 

 reefs outside the Barrier, such as those north and 

 south of Wreck Bay. According to the old rule of 

 high land and deep water going together, (in other 

 words, the slope of the ground below water being 

 only a continuation of that above,) we should have 

 the Barrier much closer to the present land in its 

 more abrupt and lofty portions than in those which 

 w T ere lower and less highly inclined. We see accord- 

 ingly the reefs approach the present land about Cape 

 Melville, where the land is steep and lofty, and 

 recede from it as we go further north in proportion 

 as the land becomes flatter and more gentle in 



