April, 

 1826. 



312 VOYAGE TO THE 



The tides in all harbours formed by coral reefs are 

 very irregular and uncertain, and are almost wholly 

 dependant upon the sea-breeze. At Toanoa it is 

 usually low water about six every morning, and high 

 water half an hour after noon. To make this devia- 

 tion from the ordinary course of nature intelligible, 

 it will be better to consider the harbour as a basin, 

 over the margin of which, after the breeze springs 

 up, the sea beats with considerable violence, and 

 throws a larger supply into it than the narrow chan- 

 nels can carry off in the same time, and consequently 

 during that period the tide rises. As the wind 

 abates the water subsides, and the nights being ge- 

 nerally calm, the water finds its lowest level by the 

 morning. 



