42 THE OCEAN. [Book 11, 



The basin of the Arctic Ocean thus forms a part 

 of the Arctic district of the Atlantic Ocean : and, 

 therefore, the stream which on the eastern side of 

 the Atlantic flows northwards from the temperate 

 zone enters the Arctic Ocean on the eastern side of 

 the Atlantic, and flows from the Arctic Ocean on the 

 western side of the Atlantic. And, in consequence 

 of the inclination of the axis of the district before 

 explained, the stream which enters the Arctic Ocean 

 passes under the axis, and that which flows from the 

 Arctic Ocean passes over the axis ; and therefore, all 

 along the coast which lies east of the entrance from 

 the Atlantic to the Arctic Ocean, the surface water 

 sets from the coast ; and, all along the coast which 

 lies to the west, the surface water sets against the 

 coast : this is so because the stream which enters 

 the Arctic Ocean is naturally an under current, and 

 is forced to the surface by the obstruction formed 

 by coast-lines, as shown in Plate X. 



In the southern hemisphere the oceans communi- 

 cate freely through the comparatively wide and deep 

 expanse of water lying between Cape Horn and the 

 South Shetlands in the one direction, and in the 

 other direction the communication beyond the tropics 

 is still more free. Besides this, there is a vast extent 

 of earth's surface in high southern latitudes which 

 has not yet been explored, and which may therefore, 

 as far as our knowledge from actual observation is 

 concerned, consist of either land or water. Since, 



