FOREST TREES 



205 



the forest poorer by destroying the vegetable matter and 

 thus retard the growth of the surviving trees. The old 

 method of boxing young pine trees in order to make 

 turpentine (as in Fig. 133) causes them to catch fire more 

 easily than they otherwise 

 would. The new method 

 of collecting sap for tur- 

 pentine, using cups and 

 metal gutters, is much 

 better for the tree (Fig. 



134). 



Uses of forests. For- 

 ests not only furnish lum- 

 ber, material for paper, 

 and scores of useful arti- 

 cles, but they decrease 

 floods. When rain falls 

 on the soil of a forest 

 that has never been burnt 

 over, it sinks into the 

 mellow soil and slowly 

 drains away to the creeks, 

 which carry off the water 

 without overflowing. 



When the trees are CUt, FlG - ' 33- THE OLD METHOD OF BOXING 



PINE TREES FOR TURPENTINE 



the surface loses its layer 



of leaves and becomes hard, so that when heavy rains 



occur, the water rushes rapidly down the slope, washes 



sand and soil into the creeks, and overflows the bottom 



lands. 



