LAND AND SEA BREEZES. 99 



for the most part, deflected trade-winds. And they 

 owe their deflection to the presence of large con- 

 tinents. If there were no land near the equator, 

 the trade- winds would always blow in the same 

 manner right round the world ; but the great con- 

 tinents, with their intensely-heated surfaces, cause 

 local disturbance of the trade- winds. When a 

 trade- wind is turned out of its course, it is regarded 

 as a monsoon. For instance, the summer sun, 

 beating on the interior plains of Asia, creates such 

 intense heat in the atmosphere that it is more than 

 sufficient to neutralize the forces which cause the 

 trade- winds to blow. They are, accordingly, arrested 

 and turned back. The great general law of the 

 trades is in this region temporarily suspended, and 

 the monsoons are created. 



It is thus that the heated plains of Africa and 

 Central America produce the monsoons of the 

 Atlantic, the Pacific, and the Gulf of Mexico. 



We think it unnecessary to explain minutely the 

 causes that produce variation in the monsoons. 

 Every intelligent reader will readily conceive how 

 the change of seasons and varied configuration as 

 well as unequal arrangement of land and water, 

 will reverse, alter, and modify the direction and 

 strength of the monsoons. 



Land and sea breezes are the next species of wind 

 to which we would direct attention. They occur in 

 tropical countries, and owe their existence to the 

 fact that the land is much more easily affected by 



