322 PHYSICAL GEOGRAPHY. 



lations than those of mean animal temperature must be sought. 

 Taking only one example, the cultivation of the vine, 

 the production of drinkable wine ( 396 ) requires not only a 

 mean annual temperature of above 9 J Cent, (or 49 .2 Fall.), 

 but also a winter temperature of above 0.5 Cent. (32. 8 

 Pah.), followed by a mean summer temperature of at least 

 18 Cent. (64.4 Pah.) At Bordeaux, in the valley of the 

 Gaioime, in lat. 44 50', the mean temperature of 

 the year, the winter, the summer, and the autumn, are 

 respectively 13.8, 6.2, 21.7, and 14.4 Cent. (56.8, 

 43 2, 71.0 and 58.0 Pah.) On plains in the vicinity of 

 the Baltic in lat. 52J, where a wine is produced which 

 though it is used can scarcely be called drinkable, these num- 

 bers are respectively 8.6, 0.7, 17.6, and 8.6 Cent. 

 (47.5, 30.8, 63.7, and 47.5 Pali.) If it should appear 

 strange that these great differences in the influence of cli- 

 mate on the production of wine do not shew themselves still 

 more markedly in the indications of thermometers, it should 

 be remembered that an instrument suspended in the shade, 

 and carefully protected from the direct rays of the sun, and 

 from nocturnal radiation, cannot shew at all seasons of the 

 year, and during all the periodical changes of temperature, 

 the true heat of the surface of the ground, which receives 

 the whole effect of the sun's rays. 



The relation of the mild, equable, littoral clim,ate of the 

 peninsula of Brittany, to the colder winters and hotter sum- 

 mers of the more compact mass of the rest of France, re- 

 sembles, to a certain degree, the relation of the climate of 

 Europe generally to that of the great continent of Asia, 

 of which it is the western peninsula. Europe owes its mildei 

 climate to its intersected form and deeply indented coast, 



