TEMPERATURE 83 



same latitude some distance to the westward ; 

 in the Atlantic the temperature rises to 59° F. 

 in the Gulf of Guinea, or six degrees warmer 

 than it is to the westward. In the Indian 

 Ocean the temperature rises to 60° F. in the 

 Bay of Bengal, or four degrees higher than 

 it is to the southward and westward. This 

 pronounced increase of temperature is ascribed 

 to two causes : (1) the monsoonal deflection 

 of the trade-winds, for some distance out 

 to sea, out of their course to westward, so as 

 to blow towards and in upon the heated land 

 of the continents, carrying the warm waters 

 towards the coast, this cause operating 

 strongest during those months when atmos- 

 pheric pressure is lower in the interior than 

 on the coast ; (2) the back water or counter 

 equatorial current to the east, which sets in 

 particularly in the eastern division of the 

 region of calms between the north and south 

 trades. 



It is noteworthy that in the equatorial 

 region of the eastern Pacific to the north of 

 the equator a very low temperature (50° F.) 

 is found at a depth of 100 fathoms, whereas 

 at the same depth to the south of the equator, 

 at a distance of only eighteen degrees of 

 latitude, the temperature is very high (72° F.). 

 This striking example is typical of the dis- 

 tribution of temperature over the greater 



