260 VOYAGE TO THE 



°vm' tnat ^ ne vesse ^ went to pieces in that spot, for had 

 ^— ~v— ' the sea been heavy enough to wash the anchor from 

 S. deeper water, the boiler must have been carried 

 much beyond it ; and the question is, whether the 

 hull of a vessel of the Matilda's tonnage could be 

 washed upon a reef dry at low water, and be depo- 

 sited two hundred yards within the usual break of 

 the sea. The circumstance of the hatches, staves of 

 casks, and part of the vessel, being deposited in parts 

 of the dry land not far distant, and scarcely more 

 than four feet from the present level of the sea, 

 offers a presumption that the sea did not rise more 

 than that height above its ordinary level, or it would 

 have washed the articles further and left them in the 

 lagoon, whence they would have been carried to sea 

 by the current. 



The materials were not in the least overgrown 

 with coral, nor had they any basin left round them 

 by which the progress of the coral could be traced ; 

 and yet, in other parts of this reef, we noticed the 

 chama gigas of seven or eight inches in diameter so 

 overgrown by it, that there was only a small aper- 

 ture of two inches left for the extremity of the shell 

 to open and shut. 



When the attention of men of science was called 

 to these singular formations by the voyages of Cap- 

 tain Cook, one opinion, among others respecting 

 their formation was, that they sprung from a small 

 base, and extended themselves laterally as they grew 

 perpendicularly towards the surface of the sea ; and 

 that they represented upon a large scale the form 

 which is assumed by some of the corallines. In 

 particular this theory was entertained by Mr. John 

 R. Forster, who accompanied Captain Cook on his 



