VOVAGE TO MADAGASCAR. 337 



trcadth. The depth of the bafm is about 

 fifty fathoms : it is capable of containing 

 ten large veffcls, which may anchor along- 

 fide of each other in from thirty to thiity- 

 five feet of water. The ground is fare ; 

 but, in the winter feafon, the entrance is 

 ihut by a fliifting fand^bank, which is diffi- 

 pated when the fouth-eaft fucceed the north 

 winds or calm weather. The fea never 

 rifes or falls more than four or five feet at 

 the time of fpring or neap-tides. During 

 the latter the reef of rocks appears above 

 the water ; and abundance of natural pro- 

 dudions may be then found on them, fuch 

 as mofles, marine plants, black coral, valua- 

 ble madrepores, fea ftars, infers, and fhells, 

 which by the variety of their form, and the 

 brilliancy of their colours, ferve to orna- 

 ment the cabinets of the , curious. The 

 mouths of the rivers here are bordered with 

 mangles which are loaded with oyfters of 

 Z aa 



