494 



PHYSICAL GEOGRAPHY. 



Europe. 



XT . fLat. 41 

 NapleS lTemp.63-3 



Asia. 



Pekin 



America. 



Philadelphia ( Lat - ^ 

 I Temp. 53-4 



.Temp. 54-8 



It is also the case, that the western region of North America, between the Rocky 

 Mountains and the Pacific Ocean, is warmer than the eastern between the Alleghanics 

 and the Atlantic ; and it was once imagined, that, comparing the two sides of the Alleghany 

 mountains, the country to the westward, including the states of Ohio and Tenessee, and 





<**^*^: 



Alleghany Mountains. 



the vast basin of the Mississippi, had a milder climate, than the Atlantic states to the east 

 ward, under the same parallels. But the mean temperature is nearly equal on the east 

 and west of the range ; and the more northerly migration of certain vegetables on the 

 western side, which originated the surmise, is referable to the Mississippi valley, lying in 

 that direction, favouring their transport, while in the eastern provinces the valleys are 

 transverse, and consequently offer no facility to their passage to the north. It cannot, 

 however, be doubted, taking the whole continent into consideration, that the eastern 

 districts of North America are colder than the western ; and in proceeding from Western 

 Europe, in an easterly direction, there is a gradual increase of cold experienced. Thus at 

 St. Petersburg it is 3 colder than at Upsal on the same parallel, and 5 colder at Moscow 

 than at Copenhagen. 



It is an interesting point to determine the cause of the greater warmth experienced 

 under the meridian of London, and through the whole of Western Europe, than in cor 

 responding latitudes. There can be no doubt that the solution is to be found in the warm 

 water of the Gulf stream in the North Atlantic, and the prevalence of west and south 

 west winds. We have before referred to this remarkable current of warm water, not 

 inferior to the Mediterranean in its extent, which sweeps through the ocean towards the 

 continent of Europe, having a temperature from 3 to 10 higher than that of the 

 contiguous sea. The winds that blow over it have its character impressed upon them, 

 and rush up from the west and south-west, invading Europe from Cape Finisterre to 

 the North Cape with currents of warm air, reaching into the heart of the continent to the 

 plains of Russia, through the great gate between the Scandinavian and the Harz 

 mountains. It may be objected to this, that the Gulf stream ought in a similar manner 



