84 



A PRIMER OF FORESTRY. 



when only tlie top of a thick layer of duff is dry enough 

 to buru. The heat may not be great enough to kill any 

 but the smallest and tenderest young trees, but that 

 does not mean that such fires do no harm. The future 

 of the forest depends on just such young growth, and 

 whenever the forest floor, which is so necessary both 



to the trees and for the 

 water sux:>ply, is injured or 

 destroyed by fire, the for- 

 est suffers liarm. 



SURFACE FIRES. 



Surface fires may be 

 checked if they are feeble 

 l)y beating them out with 

 green branches, or by rak- 

 ing the leaves away from a 

 narrow strip across their 

 course. The best tool for 

 this i^urpose is a four-tined 

 pitchfork, or a common stable fork. In sandy regions 

 a thin and narrow belt of sand is easily and quickly 

 si^rinkled over the ground with a shovel, and will check 

 the spread of a weak fire, or even of a comparatively 

 hot one if there is no wind. I)irt or sand thrown on a 

 burning fire is one of the best of all means for initting 

 it out. (See fig. 70.) 



In dense forests with a heavy forest floor, fires are 

 often hot enough not only to kill the standing timber, 

 but to consume the trunks and branches altogether, 

 and even to follow the roots far down into the ground. 

 In forests of this kind fire spreads easily, creeping along 

 on the surface or through the duff or under the bark 



Fig. 79. — A surface fire burning slowly 

 against the wind. Southern New 

 Jersey. 



