CHARACTERS OF THE TEMPERATE CLIMATE 413 



Proximity to the sea generally operates as a moderating influence on 

 climate. A mild climate may accordingly be described as a maritime 

 climate, an excessive climate as a continental climate. Besides the property 

 possessed by masses of water of heating up or cooling down more slowly 

 than solid land, the effects of ocean currents play an important part on 

 the climate of littoral districts and islands. The western parts of the British 

 Isles and the west coast of Norway owe to the Gulf Stream their high 

 winter temperature, that is so remarkable considering their high latitudes ; 

 and the east coast of North America is for similar reasons warmer than 

 its west coast. The following table gives the mean temperature for a series 

 of climates : — 



MEAN TEMPERATURES (CENTIGRADE) IN DIFFERENT CLIMATES. 

 Stations 1 to 6 Temperate; 7-S Semi-temperate; 9-12 Extreme. After O. Peschel. 



Annual fluctuations of temperature are much smaller in the south 

 temperate zone than in the north ; only the diurnal oscillations in the 

 south temperate zone are as great or greater at certain places, for 

 instance in the interior of South Africa and of Australia. 



On the whole, the temperature of the atmosphere diminishes with 

 increasing distance from the tropics, but in a most irregular manner, 

 so that isotherms in the temperate zones exhibit much greater curvatures 

 than within the tropics (see Map IV) : — 



1 February. 



2 August. 



