PHYSICAL CLIMATE. 



493 



district, the myrtle, the Camellia japonica, the Fuchsia coccinea, the Buddleia globosa 

 pass the winter without shelter in the open ground, and orange trees are seen on 

 espaliers, only sheltered, as at Rome, by means of matting. On the coasts of Brittany, in 

 the department of Finisterre, the arbutus, the pomegranate tree, the Yucca gloriosa 

 and AloifoUa, the Erica Mediterranea, the ffortensia, the Fuchsia, and the Dahlia, resist 

 in open ground the winter, the mean temperature of the peninsula being above 56 3'; 

 and Humboldt states, that in the interior of France, where the land is not much elevated 

 above the sea, we must go south 3 of latitude in order to find an annual temperature 

 equal to it. The milder winter of places on the Atlantic coast of France, as compared 

 with interior situations of corresponding latitudes, appears from the table : 



Interior countries likewise, which abound with rivers, lakes, and marshes, are less subject 

 to the extremes of heat and cold than those which have an opposite physical character. 

 The heat experienced upon the well-watered plains of Hindustan is never so excessive 

 as in the dry corresponding regions of Northern Africa ; and ai'ound the Canadian lakes, 

 the winter is milder than in other localities under the same latitude. There is an anomaly 

 in climate, which is very satisfactorily explained by a reference to the temperature of 

 the adjoining ocean. This is the well-known fact, that in travelling from the equator 

 northward to the pole, the cold increases in a slower ratio about the meridian of London, 

 than in any other part of the world. The climate of western Europe in general is 

 milder than that of countries under the same parallel at its eastern extremity, or in Asia, 

 or in America. The decrement of the mean annual temperature in Western Europe and 

 in North America, prolonging the scale to the equator, is given in the following table 

 from Humboldt : 



Thus, at the latitude of 40, that of Madrid and Philadelphia, the mean annual temperature 

 of "Western Europe is 9 higher than that of North America. At latitude 60, that of 

 St. Petersburg, Upsal, Christiania, South Shetland, the south point of Greenland, the 

 north point of Labrador, and the lower extremity of the Great Slave Lake, it is 16 higher, 

 and 33 higher at latitude 70. A similar difference appears in favour of Western 

 Europe comparing it with Eastern Asia. 



