Win*. 89 



night as through the day, as the difference be- 

 tween the temperature of the land and the 

 water will not be so great during the night; 

 and difference of temperature between two 

 points usually means a proportional difference 

 in the velocity of the wind. There is a time 

 in the fall and spring, while there is a struggle 

 betw>en the temperature of the land and water 

 for supremacy, when the winds are variable, 

 attended with local storms somewhat as we 

 have them in the temperate zone. But after 

 the sun has moved south to a sufficient extent 

 the land of India loses more heat at night than 

 is stored up in the day; hence the conditions 

 during the winter months are reversed, the 

 water is constantly warmer than the land, and 

 there is a constant wind blowing from the 

 land to the ocean, which continues until April, 

 when after a season of local storms the condi- 

 tions are established in the opposite direction. 

 These winds are called " monsoons." 



The word monsoon is probably derived from 

 an Arabic word meaning " seasons." It is a 

 peculiarity of this monsoon that in summer it 

 blows in a northeasterly direction from the sea 

 and in the winter in a southwesterly direction 

 from the land. This divergence from a direct 

 north and south is caused by the rotation of 

 the earth and the explanation is the same as 

 that we have given for the trade winds. 



In the southern latitudes there is a com- 



