258 CONFIGURATION OF LAND AND WATER. SECT. XXVI. 



leaves of a single plant of helianthus three feet high ex- 

 posed nearly forty feet of surface ; and if it be con- 

 sidered that the woody regions of the river Amazons, 

 and the higher part of the Oroonoko, occupy an area of 

 260,000 square leagues, some idea may be formed of 

 the torrents of vapor which rise from the leaves of the 

 forests all over the globe. However, the frigorific 

 effects of their evaporation are counteracted in some 

 measure by the perfect calm which reigns in the tropi- 

 cal wildernesses. The innumerable rivers, lakes, pools, 

 and marshes interspersed through the continents absorb 

 caloric, and cool the air by evaporation ; but on account 

 of the chilled and dense particles sinking to the bottom, 

 deep water diminishes the cold of winter, so long as ice 

 is not formed. 



In consequence of the difference in the radiatmg and 

 absorbing powers of the sea and land, their configuration 

 greatly modifies the distribution of heat over the surface 

 of the globe. Under the equator only one- sixth part of 

 the circumference is land ; and the superficial extent of 

 land in the northern and southern hemispheres is in the 

 proportion of three to one. The effect of this unequal 

 division is greater in the temperate than in the torrid 

 zones, for the area of land iu the northern temperate 

 zone is to that in the southern as thirteen to one, where- 

 as the proportion of land between the equator and each 

 tropic is as five to four. It is a curious fact noticed by 

 Mr. Gardner, that only one twenty-seventh part of the 

 land of the globe has land diametrically opposite to it. 

 This disproportionate arrangement of the solid part of 

 the globe has a powerful influence on the temperature 

 of the southern hemisphere. But besides these greater 

 modifications, the peninsulas, promontories, and capes, 

 running out into the ocean, together with bays and in- 

 ternal seas, all affect temperature. To these may be 

 added the position of continental masses with regard to 

 the cardinal points. All these diversities of land and 

 water influence temperature by the agency of the winds. 

 On this account the temperature is lower on the eastern 

 coasts both of the New and Old World than on the 

 western ; for considering Europe as an island, the gen- 

 eral temperature is mild in proportion as the aspect is 



