2$0 VOYAGE IN 5EARCIT 



felves by letting go the anchor, for it would not 

 reach the ground, even quite clofe to thefe walls 

 of coral, which rife perpendicularly from the bot- 

 tom of the waters. Thcfe polj/parii, whofe con- 

 tinual growth obftrucls more and more the bo- 

 fom of the deep, may well be a terror to navi- 

 gators ; and a great many fhoals, which at this 

 day afford a paffage, will, ere long, form reefe 

 extremely dangerous. 



The magnetic needle experienced little va- 

 riation during the whole time that we were fail- 

 ing along this immenfe chain of rocks, fince, 

 from their fouthern extremity, where it was ob- 

 ferved to be 11 degrees eat!, it had diminifhed 

 only two degrees, when we had reached its 

 northern extremity. 



The next day, the 3d, in branding to the 

 north north- eafl, we faw no more breakers. 



On the 7th, about half paft nine o'clock at 

 night, the moon having rifen nearly 15 degrees 

 above the horizon in the caft, we had in the 

 weft the fight of a lunar rainbow ; it differed 

 from the folar rainbow only by its colours not be- 

 ing fp brilliant. This phenomenon is far lefs 

 frequent, than it is natural to expect. 



We were now reduced to a very fcanty al- 

 lowance of water, which was a prodigious in- 

 convenience, in latitudes fo near the line, and 

 there were no means of procuring more, although 



we 



