366 
SURVEY OF THE INTERTROPICAL 
1820. the preceding years are inserted in the Appen- 
Juiy.28. dix, it will be sufficient here merely to record 
the position of the observatory ; it was situated 
on the south shore opposite the low sandy north 
point ; and was found to be in 
Latitude 15° 27' 4". 
Longitude ....... 145° 10' 49". 
Variation of the compass 5° 13f' E. 
Dip of the south end) 0 
of the Needle . .) 
High water at fulh , 
V at eight o clock, 
and change. j 
29. On the 29 th Mr. Redwell went to Captain 
Cook’s Turtle Reef, but he was unsuccessful in 
his search for that animal ; neither did he find 
any shells different from what we had previously 
seen; only a few clams ( chama gigas ) were 
brought away, besides a small fish of the shark 
tribe ( squalus ocdlatus , Linn.) At high water 
the reef was overflowed excepting at its north- 
west end, where a patch of sand not larger than 
the boat was left dry. At low tide the key, or 
the ridge of rocks heaped up round the edge of 
the reef, was left dry, and formed a barricade for 
the interior, which is occupied by a shallow lake 
of circular shape, in which many small fish and 
some sharks were seen swimming about. It was 
from this reef that Captain Cook, during the re- 
pair of his ship, procured turtle for her crew; and, 
