FOREST PLANTING. 107 



is remarkable that there is so little direct evidence on 

 the subject. 



The effect of the forest on precipitation then is not 

 free from doubt, and we cannot positively affirm that the 

 total annual quantity of rain is diminished or increased 

 by the destruction of the woods, though both theoretical 

 considerations and the balance of testimony strongly 

 favor the opinion that more rain falls in wooded than in 

 open countries. One important conclusion, at least, upon 

 the meteorological influence of forests is certain and 

 indisputed: the proposition, namely, that within their own 

 limits and near their own borders, they maintain a more 

 uniform degree of humidity in the atmosphere than is 

 observable in cleared grounds. Scarcely less can it be 

 questioned that they promote the frequency of showers, 

 and if they do not augment the amount of precipitation, 

 they equalize its distribution through the different 

 seasons. 



It is frequently asserted by dwellers upon the Plains 

 that a perceptible change has taken place in the climate 

 since the introduction of railroads and the settlement of 

 the small portion of territory already occupied. Intelli- 

 gent men express their full conviction that rainfalls are 

 more frequent, and the climate generally is less liable to 

 sudden changes and extreme variations than formerly. 

 It is hardly within bounds of possibility, however, that 

 any essential change can have been effected by the 

 settlement of a portion so insignificant in comparison 

 with the whole area. The following interesting extract 

 from a letter I have recently received from Mr. Wm. N. 



