376 PHYSICAL GEOGRAPHY OF THE SEA, AND ITS METEOROLOGY. 



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 diiference between the changing of 

 the monsoons in the spring and in the antimm 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 w^est monsoon. This 

 is the only north-west monsoon which is found in the southern 

 hemisphere. While in the northern hemisphere the north-east 

 trade-wind 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, w^e 

 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. 



704. Tfiunder and lightning. — " In the Java Sea, during the 

 month of FebiTiary, the west monsoon blows strong almost con- 

 tinually; in March it blows intermittingly, and wdth hard 

 squalls ; but in April the squalls become less frequent and less 

 severe. Now the changing commences ; all at once gusts begin 

 to spring np from the east : they are often followed by calms. 

 The clouds which crowd themselves npon the clear sky give 

 warning of the combat in the upper air which the currents there 

 are about to wage with each other. The electricity, driven 

 thereby out of its natural channels, in which, unobserved, it has 

 been performing silently, but with the full consciousness of its 

 power, the mysterious task appointed to it, now displays itself 

 with dazzling majesty ; its sheen and its voice fill wdth astonish- 

 ment and deep reverence the mind of the sailor — so susceptible, 

 in the presence of storm and darkness, to impressions that inspire 

 feelings both of dread and anxiety, which by pretended occupa- 



