INFLUENCE OF FORESTS ON CLIMATE. 17 



and while it cannot be urged that the preservation of 

 forests, however extensive, will insure a country against 

 the recurrence of disastrous floods, they certainly do have 

 a modifying influence on the water that flows from the 

 higher to the lower levels, and finally reach the brooks 

 and larger streams. Before any considerable amount 

 of water can pass from forest-covered regions, the great 

 deposits of vegetable matter covering the land must 

 necessarily become saturated and then only will there be 

 an overflow, besides the leaf-mould, sticks, brush, logs, 

 and similar materials, whicli are more or less abundant in 

 all forests, aid in retarding the flow, even after the 

 absorption has ceased — hence, we can readily understand 

 how a large vohime of water may be held in check, and 

 prevented from a rapid descent to the streams below. 

 The leaves, twigs, and rough bark on the larger brandies 

 and stems of the trees, also intercept the rain falling 

 upon them, and thus diminish the amount of water that 

 would otherwise reach the earth. 



TREES FOR SHELTER. 



Pioneers in heavily-wooded regions are usually anxious 

 to rnake a clearing, and as every tree felled not only in- 

 creases the area which he is to cultivate, but extends his 

 view, the axe is often kept in use long after there is any 

 necessity for the purpose of obtaining land for cultiva- 

 tion. In a few years the settler, who was at first so 

 anxious to open up the country, finds he has gone a little 

 too far in this direction for his own comfort and that of 

 his animals, for on taking down the screen he has not 

 only admitted the cold winds of winter, but those of 

 summer sweep over his fields, driving away needed mois- 

 ture — whip the fruit from his trees before it is ripe, and 

 otherwise causes loss that might have been prevented. 

 It is then that he begins to feel the need of protection, 



