PROTECTION OF FORESTS FROM FIRE 247 



flammable material in a forest to make possible a damag- 

 ing fire. There must also be roads, trails, or fire-lines 

 giving ready access to the forest, so that fires may be 

 located and reached. Nor are these together sufficient, 

 for there must be a constant watching for fires in order 

 that they may be discovered and attacked when they are 

 small and easily controlled, and before they have done 

 much injury. All the measures of fire protection are 

 used together, and supplement each other. 



Disposal of Slash. — The presence of dry tops and 

 piles of brush in the forest constitutes the greatest menace 

 from fires. The severity of a fire, and hence the damage 

 done, is in direct proportion to the amount of dry debris 

 on the ground. Still more serious is the fact that the 

 presence of this material makes it exceedingly difficult to 

 control and extinguish a fire. If there is no material on 

 the ground other than the ordinary leaf litter, a surface 

 fire may be easily extinguished. Old logs, dead and 

 down trees, and snags King about on the ground are also 

 a great hindrance to fighting fires, for when once ignited 

 they are apt to smolder for long periods, and so continue 

 to threaten a further spread of the flames. In many of 

 our forests the dead, standing snags constitute a very 

 dangerous feature. If these are surrounded by a dense 

 stand of conifers, they often carry the flames up into the 

 canopy and make a crown fire; if isolated, they may burn 

 for days, and finally fall, throwing sparks in all direc- 

 tions. The forester aims to reduce the amount of this 

 inflammable debris in a forest as rapidh'as possible, since 



