170 



Mr. Hinds on Climate in connexion 



with storms and heavy rains, are the prevailing climate 

 throughout the year. Beyond this, and extending a few de- 

 grees outside the tropics in both hemispheres, the trade winds 

 blow 5 they are remarkable for their regularity, uniform tem- 

 perature, and general absence from rains. 



The tropics ceasing at 23° 28', another change occurs in the 

 disposition of the year, extending to the thirty-fifth or fortieth 

 parallel. There are now two dry and two wet seasons. The 

 wet seasons occupy the periods corresponding to our spring 

 and autumn. The former is usually trifling, and the autumnal 

 fulfills the chief duties of the rainy season. Towards the 

 limits of this subtropical climate frosts are not unfrequent, 

 but snow is rarely observed. From 40° to 60° four regular 

 seasons rule the year, familiar to us under the divisions of 

 spring, summer, autumn, and winter, each possessing its pe- 

 culiarities. 



Beyond the sixtieth parallel, as far as our knowledge ex- 

 tends, only two seasons exist. These are not characterized 

 by the presence or absence of rain as in lower latitudes, but 

 by the intensity of the range of temperature. Summer and 

 winter succeed each other with singular rapidity. The snow 

 which covers the soil is represented as melting in the short 

 space of fifty or sixty hours, and exposing a vegetation already 

 in its bloom. The intensity of the sun's rays over the tem- 

 perature of the air is particularly remarkable, and the great 

 length of the day, or, in other words, the continued presence 

 of the sun above the horizon, causes an accumulation of heat, 

 mentioned by our northern voyagers as excessive. Hail is 

 here unknown. 



Malte-Brun enumerates nine circumstances as developing 

 climate, the whole of which tend to influence the temperature. 

 If the globe presented an uniform surface throughout, con- 

 sisting of the same material, and equally reflecting, absorbing, 

 and radiating heat, the distribution of the temperature, from 

 the equator to the poles, w ould advance in regular progression ; 

 but there is such variety in the arrangement of land and wa- 

 ter, elevation of surface, and in the investing productions, that 

 every spot displays an union of causes, militating against a 

 regular distribution of temperature. 



The most natural view to be taken of climate will regard the 

 relative distribution of temperature and moisture ; for though 

 several other agents are subservient, these two will constantly 

 be found to preside*. In this manner it will be easy to sketch 



* The subject of the Distribution of Temperature on the surface of the 

 Earth has been elaborately investigated by Professor Dove of Berlin in two 

 works published in 1840, 1841. abstracts of which by H. Croft, Esq., will 

 be found in Part X. of Taylor's ' Scientific Memoirs.' — En. 



