MONSOONS. 361 



of latitude. In the Indian Ocean, its middle is between the 

 equator and 5° S. ; in the Pacific, between the equator and 5° N. ; 

 in the Atlantic, between 5° and J 0° N. In the Atlantic it is a 

 summer monsoon easily to be accounted for. This belt of sub- 

 monsoons, considering its great length and small breadth, is one 

 of the most remarkable phenomena in marine meteorology. 



703. The north-west monsoons of Australia come from this 

 The monsoons of ^clt ; there it is widened, for these winds extend 

 Australasia. f^j- dowu the wost coast of that continent. The 



Malayan and Australasian archipelago have a complication of 

 monsoons and sub-monsoons. The land and sea breezes impart 

 to them peculiar features in many places, especially about the 

 changing of the monsoons, as described by Jansen in his appendix 

 to the Dutch edition of this work : " We have seen," says he, 

 " that the calms which precede the sea breeze generally continue 

 loDger, and are accompanied with an upward motion of the air ; 

 that, on the contrary, those which precede the land breeze are, 

 in the Java Sea, generally of shorter duration, accompanied by a 

 heavy atmosphere, and that there is also an evident difference 

 between the conversion of the land breeze into the sea breeze, 

 and of the latter into the former. Even as the calms vary, so 

 there appears to be a marked difference between the changing of 

 the monsoons in the spring and in the autumn in the Java Sea. 

 As soon as the sun has crossed the equator, and its vertical rays 

 begin to play more and more perpendicularly upon the northern 

 hemisphere, the inland plains of Asia, North Africa, and of North 

 America are so heated as to give birth to the south-west mon- 

 soons in the China Sea, in the North Indian Ocean, in the North 

 Atlantic, and upon the west coast of Central America : then the 

 north-west monsoon disappears from the East Indian Archipelago, 

 and gives place to the south-east trade-wind, which is known as 

 the east monsoon, just as the north-west wind, which prevails 

 during the southern summer, is called the west monsoon. 

 This is the only north-west monsoon which is found in the south- 

 ern hemisphere. While in the northern hemisphere the north- 

 east trade-v/ind blows in the China Sea and in the Indian Ocean, 

 in the East Indian Archipelago the west monsoon prevails ; and 

 when here the south-east trade blows as the east monsoon, we 

 find the south-west monsoon in the adjacent seas of the northern 

 hemisphere. Generally the westerly monsoons blow during the 

 summer months of the hemisphere wherein they are found. 



