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HYDROGRAPHY. 



YALANGALALA. 



Yalangalala is a small island, of moderate height, forming the 

 southern point of the Nanuku Passage. It is situated in the southern 

 bight of a very extensive reef, which surrounds it, extending from 

 the island to the west-northwest 4 miles, when it again turns to the 

 northeast 4£ miles, then to the southeast and around the island ; the 

 southeast end is overlapped by the Duff Reef, which trends south- 

 southeast and north-northwest for the distance of 6 miles, to the sandy 

 island of Volerara, which rises from near the southern end. 



Yalangalala is uninhabited, and only resorted to in the turtle 

 season. These reefs, notwithstanding they can be distinctly seen by 

 the sea breaking occasionally on them, are very dangerous, particu- 

 larly in boisterous weather, and from the fact that there is a strong 

 set to the northward, sometimes as much as a mile and an eighth per 

 hour. 



NANUKU. 



West-northwest of Yalangalala lies the island of Nanuku, which 

 gives the name to the passage between the two ; between the nearest 

 points of the reefs surrounding these islands it is 15 miles. The 

 Island of Nanuku lies in the southeast bight of its reef, is low, well 

 covered with trees, and 1J miles in length, by half a mile wide. The 

 reef which encloses it is one of the most extensive in the group, being 

 14 miles in length, by 8 miles in width, in shape nearly a parallelo- 

 gram, and embracing an area of 110 square miles. Throughout this 

 whole extent there is no opening, and the sea within is as blue as the 

 ocean. 



NUKUMBASANGA AND NUKUMANU. 



Nukumbasanga and Nukumanu are two small islands, lying 10 

 miles to the north of the reef of Nanuku. They lie in a direction 

 west-by-south and east-by-north from each other, and are surrounded 

 by reefs ; the former lies to the east, and has a small islet in the 

 western part of its reef, called Otto; the reef is 2 miles long, by li 

 wide, and nearly a parallelogram in form. That which surrounds 

 Nukumanu is of irregular shape, 2$ miles in length, by II wide. 

 The Adolphus and Doughty Reefs lie between the two, and nearly 



