280 RELATION OF FORESTS TO THE 



Faeulte de Bourdemix, has given the following note as a contribu- 

 tion to the researches of M. C6zanne : — 



"In 1868 and in 1869 I established as a fact that in Northern 

 and Central Europe, and in Siberia, on to Kamschatka, there had 

 been a predominance of rain during three months of summer, the 

 more marked as we advanced farther to the east, while in the region 

 of the Mediterranean there had been a sparsity of rain during the 

 same season. 



" It is interesting to investigate what is in France the pluvial regime 

 of the lofty chain which separates the two great orographic or 

 mountain-bound basins of northern and of southern Europe; and this 

 I shall now attempt to do by means more especially of observations 

 made by the Service des Fonts, et Chaussees, which the Tngenieurs en 

 Chef of the Alpine Departments have had the kindness to communi- 

 cate to me. 



" It might naturally be supposed, a priori, the northern regime 

 having summer rains so copious and predominant on one hand in all the 

 plains of Switzerland, and on to Lyons ; and ou the other hand in the 

 Lombardo- Venetian plain of the Adriatic, on to that of Milan, — that 

 this regime would be continued in the equally cold high mountains of 

 the western branches of the Alps, which stretch from Mont Blanc in 

 the south to Nice and Draguigan ; but it is not so. 



" In the high southern summits at the Great St Bernard, even there 

 the Mediterranean regime is deplored, and it is matter of complaint 

 that the rains of summer are scarcely two-thirds of those of spring, 

 which exceed somewhat those of autumn ; and this poverty of atmos- 

 pheric moisture in summer goes on progressingly increasing in pro- 

 portion as advancing from that northern station one approaches to 

 the Mediterranean. 



" In the High Alps, at Briangon, the rains of spring prevail still 

 more, being more than double those of the summer ; on the other 

 stations of the department. Gap and Serres, and also at Die on the 

 Drome, the rains of autumn reach on an average double the measure 

 of those of summer. 



" In the Lower Alps, at Barcelonnette, Digne, Castellane and 

 Manosque, the difference between the quantities of the rainfall in 

 summer and in autumn is still greater : it is the same on the 

 plateaus from Var to R^gusse. 



" At Valences, at Yiviers, at Orange, at Avignon, the spring rains 

 still predominate, but they are greatly exceeded by those of autumn. 



" On the coast from Marseilles to Toulon, Hy^ns and G6nes, the 



