332 COSMOS. 



should exceed 49, that the winter temperature should be 

 upwards of 33, and the mean summer temperature upwards 

 of 64. At Bordeaux, in the valley of the Garonne (44 50' 

 lat.), the mean annual winter, summer, and autumn tempera- 

 tures are respectively 57, 43, 71, and 58. In the plains 

 near the Baltic (52 30' lat.), where a wine is produced that 

 can scarcely be considered potable, these numbers are follows : 

 47-5, 31, 63-7, and 47-5. If it should appear strange 

 that the great differences indicated by the influence of climate 

 on the production of wine should not be more clearly mani- 

 fested by our thermometers, the circumstance will appear less 

 singular, when we remember that a thermometer standing in 

 the shade, and protected from the effect of direct insolation 

 and nocturnal radiation cannot, at all seasons of the year, and 

 during all periodic changes of heat, indicate the true superfi- 

 cial temperature of the ground exposed to the whole effect of 

 the sun's rays. 



The same relations which exist between the equable littoral 

 climate of the peninsula of Brittany, and the lower winter and 

 higher summer temperature of the remainder of the continent 

 of France, are likewise manifested, in some degree, between 

 Europe and the great continent of Asia, of which the former 

 may be considered to constitute the western peninsula. 

 Europe owes its milder climate, in the first place, to its posi- 



The great accordance in the distribution of the annual temperature 

 through the different seasons, as presented by the results obtained for the 

 valleys of the Rhine and Maine, tends to confirm the accuracy of these 

 meteorological observations. The months of December, January, and 

 February, are reckoned as winter months. When the different quali- 

 ties of the wines produced in Franconia, and in the countries around the 

 Baltic, are compared with the mean summer and autumn temperature 

 of Wiirzburg and Berlin, we are almost surprised to find a difference of 

 only about two degrees. The difference in the spring is about four 

 degrees. The influence of late May frosts on the flowering season, 

 and after a correspondingly cold winter, is almost as important an 

 element as the time of the subsequent ripening of the grape, and the 

 influence of direct, not diffused, light of the unclouded sun. The 

 difference alluded to in the text, between the true temperature of the 

 surface of the ground and the indications of a thermometer suspended 

 in the shade, and protected from extraneous influences, is inferred by 

 ' Dove, from a consideration of the results of fifteen years' observations 

 made at the Chiswick Gardens ; see Dove, in Bericht uber die VerhcvndL 

 der Berl. ATcad. der Wiss., August, 1844, s. 285. 



