88 THE OCEAN 



the eastern side but very greatly on the south- 

 western side ; at three stations to the east 

 of Buenos Ayres the temperature is only 

 32-6° F., which is the lowest yet observed in 

 any part of the ocean at this depth. In the 

 Indian Ocean the temperature is everywhere 

 below the mean, observations at twenty 

 stations giving an average of 34-4° F., or 0-8° 

 below the mean. A large portion of the 

 Pacific has a temperature below the mean at 

 this depth, the lowest being 33-2° F., observed 

 to the south of Kamchatka, but throughout 

 the cold area of the Pacific generally the 

 deficiency below the mean is small, so that 

 on the whole it may be said that the tempera- 

 ture of the Pacific at 2200 fathoms closely 

 approximates to the mean for all the oceans 

 at this depth, viz. 35-2° F. 



Bottom Temperature. — The surface of the 

 ocean may be regarded as a level plain, whereas 

 the floor of the ocean is an undulating plain, 

 and therefore a map showing the bottom 

 temperature, i.e., the temperature of the 

 water in actual contact with the sea-floor, 

 is very different from one showing the surface 

 temperature. At the surface of the earth, 

 both on land and at sea, the lines of equal 

 temperature run more or less parallel to the 

 equator, that is to say, in an east and west 

 direction, whereas at the bottom of the ocean 



