1893.] D. Pram — Flora of Narcondam and Barren Island. 



57 



miles east-sonth-east of Rutland Island, and the same distance due east 

 of the opening, Duncan Passage, between Rutland Island and Little 

 Andaman. The rock appears above the surface, and no more ; but though 

 so much smaller as a subaerial peak than Barren Island or JSTarcondam, 

 as a submarine peak it is evidently larger than either, since its summit 

 appears as a long narrow bank that carries from 15 to 80 fathoms of 

 water ; this bank does not extend to the east or the west for more than 

 two miles from the Rock, but towards the south extends at least 10 

 miles, to the north more than 20 miles. Beyond the edge of this bank — 

 the Invisible Bank of the Admiralty maps — the lead sinks at once into 

 deeper water. The Bank itself has been carefully surveyed but of the 

 absolute depths of the soundings just beyond we know little or nothing, 

 so that though this survey is invaluable to navigators, from a hydrogra- 

 phical point of view it leaves much to be desired. Meagre however as 

 its details are it shows that the soundings are deeper towards the east, 

 south, and west than they are towards the north. The following Table 

 indicates the soundings shown in the Admiralty maps : — 



Table III. — Soundings in the vicinity of Plat Rock. 



General 



LINE 01 



DIRECTION OF 

 SOUNDINGS. 



Distance in miles from 

 rock. 



i Depth in fathoms. 





N 



N. E. 



1 



14 







N 



N. E. 



10 



25 







N 



N. E. 



13 



27 









N. 



5 



38 









N. 



15 



80 







N 



W. 



5 



16 







N. 



W. 



10 



59 







N 



w. 



15 



168 









w 



10 



90 (no 



bottom.) 





w. 



35 



500 







s. 



w. 



8* 



78 





s. 



s. w. 



8 



35 







s. 



s. w. 



16 



200 (no 



bottom.) 





s. 



E. 



2 



16 







s. 



E. 



7 



48 







s. 



E. 



12 



200 (no 



bottom.) 



Along the east side of the bank none of the soundings made have 

 touched bottom, but they show that the edge drops into deep water 

 within 5 miles of a line running from south-south-west to north-north-east 



