106 FOREST PLANTING. 



of Asia and Northern Africa, which in ancient times were the 

 granaries of Europe, fertile and populous, similar consequences have 

 been experienced. These lands are now deserts, and it is the destruc- 

 tion of the forests alone which has produced this desolation. In 

 Southern France many districts have from the same cause become 

 barren wastes of stone, and the cultivation of the vine and olive has 

 suffered severely since the baring of the neighboring mountains. On 

 the other hand, examples of the beneficial influence of planting and 

 restoring the woods are not wanting. In Scotland, where many miles 

 square have been planted with trees, this effect has been manifest, and 

 similar observations have been made in several places in Southern 

 France." 



Monestier Savignat arrives at this conclusion : 



" Forests on the one hand diminish evaporation ; on the other they 

 act on the atmosphere as refrigerating causes. The second scale of 

 the balance predominates over the other, for it is established that in 

 wooded countries it rains oftener, and that the quantity of rain being 

 equal, they are more humid." 



Boussingault, whose observations on the drying up of 

 lakes and springs, from the destruction of the woods in 

 tropical America, have often been cited as conclusive 

 proof that the quantity of rain was thereby diminished, 

 after examining the question with much care, remarks : 



" In my judgment it is settled that very large clearings must dimin- 

 ish the annual fall of rain in a country." 



Numerous other authorities might be cited in support 

 of the proposition that forests tend to produce rain; but 

 though the arguments of the advocates of this doctrine 

 are very plausible, not to say convincing, their opinions 

 are rather a priori conclusions from general meteorological 

 laws, than deductions from facts of observation, and * 



