ii6 Temperature Sections Surveyed. 



part of the Sea of Magallanes from the North Pacific basin. Like 

 the Gulf Stream, the Kuro-Siwo imposes its name upon its 

 more powerful though less conspicuous parent. The axis of the 

 current is at Station 238, where it depresses the isotherm of 2°. 5 

 C. from its average North Pacific level at 700 fathoms down to 

 below 1000 fathoms. This axis corresponds with the axis of 

 the 4000-fathom channel, which, as formerly described, stretches 

 northward along the coast of Nipon and Yezo. The breadth of 

 the warm current, measured from its western limit off the 

 Japanese coast to beyond Station 239, is over 400 miles. At. 

 Station 240 we find ourselves in the middle of a great polar 

 current which flows down between Station 239 and Station 241 

 in a south-westerly direction, and reduces the temperature of the 

 water to a depth of more than 600 fathoms. This is the same 

 current whose course we have been tracing through the Sea of 

 Magallanes, past the Pelew Islands, into the Molucca Passage, 

 and through the Indian Archipelago into the Indian Ocean. It 

 probably divides itself into two branches, one entering the Sea 

 of Mao-allanes north of the Bonin Islands, and between the 

 Bonin and the Mariana Islands (Stations 228-231), and con- 

 tinuing its south-westerly course towards the Philippines, the 

 other turning down outside these islands into the 3000-fathom 

 basin situated north of the Carolines. 



The isotherms of the stations to the eastward of Station 240 

 indicate the existence of alternate warm and cold currents — the 

 former, branches of the equatorial current flowing first eastward, 

 then turning southward, across the parallel of lat. 40° N, ; the 

 latter, cold currents from the sea of Okhotsk and the Behring 

 Sea. There are warm currents at Stations 241, 243, 246, and 

 250, cold currents at Station 242, between 244 and 245, and at 

 Station 248. A cold current seems to flow down on each side 

 of the projecting north-western extremity of the Hawaiian 

 plateau at Station 246. From Stations 248 to 253, after cross- 



