110 RELATIONS OF TREES TO WATER. 



droughts. Many ancient streams have entirely disap- 

 peared, and a still greater number are dry in summer. 

 Boussingault mentions a fact that clearly illustrates the 

 condition to which we may be exposed in thousands of 

 locations on this continent. In the island of Ascension 

 there was a beautiful spring, situated at the foot of a 

 mountain which was covered with wood. By degrees the 

 spring became less copious, and at length failed. While 

 its waters were annually diminishing in bulk, the moun- 

 tain had been gradually cleared of its forest. The dis- 

 appearance of the spring was attributed to the clearing. 

 The mountain was again planted, and as the new growth 

 of wood increased, the spring reappeared, and finally at- 

 tained its original fulness. More to be dreaded than 

 drought, and produced by the same cause, the clear- 

 ing of steep declivities of their wood, are the exces- 

 sive inundations to which all parts of the country are 

 subject. 



If it were in the power of man to dispose his woods 

 and tillage in the most advantageous manner, he might 

 not only produce an important amelioration of the general 

 climate, but he might diminish the frequency and severity 

 both of droughts and inundations, and preserve the gen- 

 eral fulness of streams. If every man were to pursue 

 that course which would protect his own grounds from 

 these evils, it would be sufficient to bring about this be- 

 neficent result. If each owner of land would keep all his 

 hills and declivities, and all slopes that contain only a 

 thin deposit of soil or a quarry, covered with forest, he 

 would lessen his local inundations from vernal thaws and 

 summer rains. Such a covering of wood tends to equal- 

 ize the moisture that is distributed over the land, causing 

 it, when showered upon the hills, to be retained by the 

 mechanical action of the trees and their undergrowth of 

 shrubs and herbaceous plants, and by the spongy surface 



