CLIMATE. 123 



and, consequently, heats it less. Moreover, the 

 water when heated is set in motion by reason of 

 the differences of density produced by the differ- 

 ences of temperature, and moves towards colder 

 districts, and its place is taken by water that moves 

 from colder districts. Such motions are seen in 

 the constant ocean currents. 



The land, on the contrary, is heated to a com- 

 paratively small depth, remains in its place, and 

 may, therefore, rapidly become intensely hot. 



The climate produced by an extended land area 

 is called a continental climate. That produced by 

 an extended water area is called an oceanic climate. 

 The continental climate is characterized by great 

 extremes of heat and cold, that is, a continental 

 climate is apt to be very hot in summer and very 

 cold in winter. The oceanic climate, on the con- 

 trary, is characterized by a comparatively uniform 

 temperature, being neither very hot in summer nor 

 very cold in winter. 



So far as the climate of the land is concerned, 

 the differences of climate above referred to are 

 greatly influenced by the nature of the surface. 

 If the surface is covered by vegetation of any kind, 

 especially by forests, it both heats slowly and cools 

 slowly. 



