7 



from pasturage and browsing a zone along the banks of ravines, 

 which is carefully turfed and planted with shrubs and trees ; 

 consolidating the scarps of the ravines by grading and wattling 

 and establishing barriers of solid masonry, or more commonly 

 of fascines, or other simple materials across the bed of the 

 stream, and cutting narrow terraces along the scarps. Many 

 hundred ravines, formerly the channels of formidable torrents, 

 have been secured by barriers, and by grading and planting, 

 and the success of the system has far surpassed all expectation. 

 The plan of circling^ long used in this country, is now adopted 

 in France. This plan prevents the wash of tlie surface, and 

 provides irrigation by running horizontal furrows along tlie 

 hill-sides, and thus cheaply securing a succession of small 

 terraces, checking the rapid flow of the surface water, obvi- 

 ating one cause of inundations, and greatly fertilizing the 

 lands thus irrigated. 



The evils of widespread forest denudation both as regards 

 climatic changes, uniform flow of springs and streams, devas- 

 tation by mountain torrents, and the exhaustion of once fertile 

 lands, have been long and sadly felt in the Old World. Many 

 rich and fertile countries have become arid wastes when 

 denuded of trees. The Mediterranean coast of Africa is a 

 case in point. Tunis and Algiers were once fertile regions, 

 supporting a dense population. Their decadence is traceable 

 largely to the destruction of their forests. Rentzsch ascribes 

 the political decadence of Spain almost wholly to the destruc- 

 tion of the forests. 



Mr. George P. Marsh says: "There are parts of Asia 

 Minor, of Northern Africa, of Greece, and even of Alpine 

 Europe, where causes set in action by man have brought the 

 face of the earth to a desolation as complete as that of the 

 moon, and yet they are known to have been once covered with 

 luxuriant woods, verdant pastures, and fertile meadows; and 

 a dense population formerly inhabited those now lonely dis- 

 tricts. The fairest and fruitfulest provinces of the Roman 

 empire once endowed with the greatest superiority of soil, 

 climate, and position, are completely exhausted of their fer- 

 tility, or so diminished in their productiveness as, with the 



