TROPICAL RAINS. 7 



north and south of the belt of calms, we find in both lierai- 

 spheres a broad zone, characterised by two distinct rainy sea- 

 sons, separated by two equally distinct periods of dry weather. 

 The rainy seasons take place while the sun is crossing the zenith, 

 and more or less paralysing the power of the trade winds. 

 Cayenne, Honduras, Jamaica, Pernambuco, Bahia, afford us 

 examples of these well-defined alterations. In Jamaica, for 

 instance (18° N. lat.), the first rainy season begins in April, the 

 second in October ; the first dry season in June, and the second 

 in December. 



Towards the verge of the tropics follow the zones which are 

 characterised by a single rainy season, but of a longer con- 

 tinuance, generally lasting six months, throughout the summer, 

 or from one equinoctium to another. In these parts, the rainy 

 season is also the warmest period of the year, since here the 

 different height of the sun in winter and summer is already so 

 considerable, that at the time of culmination the clouds and 

 rain are not able to reduce the temperature below that of the 

 clear and dry winter months ; while in the zones which are 

 situated nearer to the equator, the rainy season, in spite of the 

 sun's culmination, is always the coolest. 



To sum up the foregoing remarks in a few words : the two 

 rainy seasons, which characterise the middle zone between each 

 tropic and the line, have a tendency to pass into one annual 

 rainy season on advancing towards the tropics, and to merge 

 into a permanent rainy season on approaching the equator. As 

 the sun goes to the north or south, he opens the sluices of 

 heaven, and closes them as he passes to another hemisphere. 



Such may be said to be the normal state which would every- 

 where obtain within the equatorial regions if one unbounded 

 ocean covered their surface, and none of the disturbing influences 

 previously mentioned interfered ; but as we find the trade winds 

 so frequently deflected from their course, we must also naturally 

 expect the general or theoretical order of the dry and rainy 

 seasons to be liable to great modifications. 



Thus, in the Indian Ocean and in the Chinese Sea, terrestrial 

 influences prevail during the summer which completely divert 

 the trade wind, there called the North-east Monsoon-, from its 

 regular path. From the wide lands of south-eastern Asia, 

 glowing, during the summer months, with a torrid heat, the 



