74 THE OCEAN 



Turning now to those portions of the sea- 

 surface where the range exceeds 10°, we find 

 that the area with a range of temperature 

 between 10° and 20° F. is the most extensive, 

 fining up the intervals between the inter- 

 tropical belt and polar areas of small range 

 just referred to, and enclosing in certain 

 positions areas with a range greater than 

 twenty degrees. 



A range exceeding 20° F. occurs in the 

 southern hemisphere south of the tropics in a 

 band continuous across the South Atlantic and 

 greater part of the South Indian Ocean with 

 isolated areas off South Australia, New Zea- 

 land and South America ; in the northern 

 hemisphere extensive areas cross the North 

 Pacific and North Atlantic, extending into 

 the Mediterranean and Baltic. 



A range exceeding 30° F. is found in two 

 large areas, one in the north-west Atlantic, 

 off the east coast of North America between 

 lat. 30° N. and 50° N., the other in the north- 

 west Pacific, off the east coast of Asia between 

 lat. 22° N. and 56° N., with smaller areas in 

 the Mediterranean and Black Sea, in the 

 Baltic and North Sea, at the heads of the 

 Red Sea and Persian Gulf, off the mouth of the 

 Rio de la Plata, and south of the Cape of Good 

 Hope and Madagascar on the parallel of 40° S. 



A range exceeding 40° F. occurs in the north- 



