

TROPICAL RAINS. 21 



their passage over this extensive empire, deposit 

 the moisture with which they are saturated gra- 

 dually and less copiously as they advance to the 

 north, till finally both one and the other become 

 exhausted as they reach Peking. 



At Macao, from March to May the increase and 

 varying relations of temperature and humidity are 

 considerable ; and the quantity of rain which falls 

 during these months, agreeably to Mr. Beale's 

 journal*, increases in a geometrical progression. 

 Towards the end of March and beginning of April, 

 the atmosphere becomes stagnant, warm, and close ; 

 mists and fogs cover the sea in the mornings, and 

 sometimes in the day ; the hygrometer attains its 

 highest range of humidity, and the air being thus 

 saturated with aqueous vapours, a considerable de- 

 position of moisture is perceptible on the painted 

 walls of houses and other surrounding objects. 



The increasing heat, evaporation, and alternation 

 of bright weather and light showers which now 

 accompany the progress of spring in April, produce 

 a warm humid state of atmosphere, the effects of 

 which are apparent in the vast stimulus given to 

 vegetation. At length commence those tropical 

 rains, accompanied with awful thunder and light- 

 ning, which precede the setting in of the S. W. 

 monsoon early in May, and continue at intervals 

 throughout that monsoon. 



* Davis's " Chinese," second edition, p. 339. 



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