450 The Influence of Forests on Climate. 



Strabo tells us that it was necessary to take great care lest 

 Babylon should be invaded by the waters. The Euphrates, he 

 says, became swollen in spring, when the snows melted on the 

 mountains of Armenia, overflowed its banks, and would have 

 submerged the cultivated lands if the superabundant water had 

 not been drawn off by canals like those of the Nile. This state 

 of things no longer exists. M. Oppert, who travelled through 

 Babylonia a few years ago, reports that the quantity of water 

 transported by the Euphrates is much less than it was in 

 former ages, that its banks do not overflow, that the canals 

 are dry, and the marshes become so during the summer heats. 

 The change, he assures us, has been produced by the destruc- 

 tion of forests on the mountains of Armenia. Choiseul Gouflier 

 could not find the river Scamander in the Troad • although it 

 was navigable in the days of Pliny, its bed is now dry, and the 

 cedars are gone that once covered Mount Ida, from whence it 

 arose. 



M. Boussaingault informs us that the valley of Aragua, in the 

 province of Venezuela, situated at a little distance from the 

 coast, is closed on all sides. The rivers which run into it do 

 not reach the sea, but give rise to the Lake of Tacarigua, which, 

 according to Humboldt, experienced at the beginning of the 

 century a gradual diminution, of which the cause was unknown. 

 The village of Nueva Valencia, founded in 1585, was then 

 only half a league from the lake, while in 1800 it was 2700 

 toises from it. In 1822, M. Boussaingault learnt from the in- 

 habitants that the waters of the lake had risen, and that land 

 formerly cultivated was then under water. For two and twenty 

 years the valley had been the scene of sanguinary struggles 

 during the war of independence, the population was deci- 

 mated, the ground uncultivated, and forests, which grow with 

 great rapidity in that climate, occupied a large portion of the 

 soil. These are the principal facts which M. Becquerel 

 brings into view. 



