18 THE COEAL REEFS OF THE MALDIVES. 



in the first sounding was composed of light-green fine coral sand with 

 numerous Globigerinae. In fourteen hundred and ninety-eight fathoms 

 we found bluish ooze with a greater number of Globigerinae. 



Line of soundings across Wadu Channel (PI. Sb, fig. 19). 



We ran a line normal to the pass between Male and Toddy Islands 

 (North Male), to Wadu Island (South Male). One mile southwest of Male 

 Island we found two hundred and sixty-five fathoms (No. 1); hard bottom. 

 In the centre of the channel the depth was somewhat less : two hundred 

 and fiftj^-nine fathoms (No. 2), hard bottom, and one mile from Wadu two 

 hundred and thirty-nine fathoms (No. 3), with broken corals and shells. 

 The deepest part of the channel is near North Male, the bottom of the 

 channel rising slightly towards South Male. The flat plateau of Wadu 

 channel extends well to the eastward, as we obtained three hundred and 

 nineteen fathoms (No. 47) nearly five miles to the eastward, about two and 

 one-half miles northeast off the outer reef flat of Huras, South Male. 



The sounding of one thousand and five fathoms two and one half miles 

 from Hulule Island, given by Mr. Gardiner,* indicates either a sharp bight 

 to the westward in the one-thousand-fathom line, or that Mr. Gardiner may 

 have used too light a weight (fifteen pounds) to run out his line. We 

 found the one-thousand-fathom line (No. 45) at least six miles off the cen- 

 tral part of the east face of South Male, and in our own soundings a sixty 

 pound shot none too heavy for the deeper soundings in passes where the 

 ciu'rents often ran with great violence. 



Everywhere in the Maldives the strong currents apj^ear to extend to the 

 bottom of the channels separating the banks ; they sweep the bottom clean, 

 and must, as has been observed by Mr. Gardiner, exert considerable in- 

 fluence in keeping them clear, and may also have greatly contributed to 

 their origin. 



Line running east of South Male, from Guru Pass (PI. 8 c, fig. 27). 

 Three miles due east of Guru Pass we sounded in nine hundred and sixty 



' Mr. Gardner's* sounding lies between our soundings of two hundred and fifty-nine (No. 2) and 

 three hundred and nineteen fathoms (No. 47) off the southeast corner of Male. 



* Loc. cit., p. l.'jS. 



