202 EFFECTS OF FOEESTS ON SPRINGS AND RIVBES. 



the ground, but flows away over the surface, and to which popularly 

 is ascribed the swelling of floods, there exists no difference of opinio* 

 in regard to the influence of forests. On aU hands it is agreed that 

 with the removal of forests the tributaries to water-courses rush more 

 rapidly to these ; and that in mountain regions, on steep precipices, 

 from which woods have been cleared, the fruitful soil is swept away, 

 and water-courses are converted into torrents, 



" In the cutting down of forests which present no longer, as 

 previously, a hindrance to the flowing off" of the rain-water by their 

 manifold united roots, by lichens and by mosses, may be seen gene- 

 rally the cause of the more frequent and extensive, and ever more 

 threatening inundations. 



" With the facts before them of the diminution of the water in 

 the rivers, which diminution is connected with a diminution in 

 the copiousness of springs, the Commission find the cause of 

 these phenomena to lie — 1. In the continued extensive destruction 

 of forests, the beneficial effects of which consist in an increased 

 humidity of the air, a reduction in the extremes of temperature, a 

 diminution of evaporation, and the securing a more regular distribu- 

 tion of the rainfall ; while the injurious effects of the destruction of 

 them is seen in an alternation of periods of drought at one time, with 

 wasting floods at another. 



" 2. In the drying up of the lakes, marshes, and bogs, which 

 increased the humidity of the atmosphere, diminished evaporation 

 elsewhere, kept down excessive heat, and finally escaped through 

 rents in the ground, increased directly the formation of springs. 



"3. In the breaking up and cultivation of extensive tracts of 

 country, for the watering of which considerable quantities of water 

 are required. 



" 4. In the increase of population and of domestic animals, although 

 the diminution of the water occasioned by these causes can amount to 

 what must be relatively a small portion of the whole. 



With Jitter. Without litter on the ground. 



In open ground, 19 — 14 11 



In the forest, 61 72 GS 36 



Difference 33 61 61 26 



Earlier experiments come to us from Maurice in Geneva, and Gasparin in Orange. 

 A later one, on a great scale— undertaken by E. Eisler at Calfeve, by Nyon (Canton 

 Wallis), who sowed different experimental fields, of 12-300 square metres, with corn, 

 clover, etc.,— determined the infiltration at 035 metres deep, and showed the 

 comparative humidity of the soil with that of the superficial soil under different 

 conditions of culture. — Anmiaire Meteorologique de I'Obsematoire de l^'oris, ponr 1873, 

 p. 277, 



