358 COCKBURN ISLANDS. 



Barrier, and thus forms a leading mark for ships 

 making their way through these reefs. 



In the evening the anchor was dropped about a 

 mile from the north side of the Bird Isles in ten 

 fathoms, a sudden degree from fifteen, just before 

 standing- in W. S. W . to the anchorage. Five miles 

 S. E. by E. from these isles, we passed close to the 

 position of a patch of shoal water, according to the 

 chart : its presence, however, was not detected, the 

 depth at the time being nineteen fathoms. The only 

 additions made to the chart durinjT the dav were 

 a few soundinufs, besides increasinof the number 

 and altering the position of Cockburn Islands, with 

 the reefs fronting them. The number of these 

 isles is thus increased from two to four ; they are 

 square rocky lumps, the largest being three hun- 

 dred feet high. The current during the day set 

 steadily N. W. almost a mile an hour. On anchor- 

 inof we found it setting- W. N. W. at the same rate. 

 At midnight it changed its direction to E. S. E. from 

 a quarter to half knot an hour. The time of high 

 water being about 6 a.m., it is evident the flood 

 stream came here from S. or S. E. The islands 

 passed during the day, were of a small lagoon cha- 

 racter and the reefs oval-shaped, with an ele- 

 vated patch of dead coral at their north extreme, 

 which had the appearance, at a distance, of sand. 

 The main land had much changed in outline, 

 having subsided into a wearisome series of undu- 

 lating hills, varying from five to seven hundred 

 feet in height. The coast was, therefore, utterly 



