39 



erablc damage to the trees so scarred unless either a 

 fire line is constructed around each one, or it is 

 protected ty piling earth and rocks about the "base - 

 a procedure prohibited on account of excessive cost. 

 A fire, no matter how light, upon coming in contact 

 with the pitchy butts of the fire-scarred trees, ig>- 

 nites them immediately, after which they will burn un- 

 til all of the resinous wood surrounding the entire 

 scar has been consumed. Only after the sear has been 

 completely charred over will the fire die out. As 

 soon as the scar cools, the tree secretes quantities 

 of resin to heal the wound, and within a week the base 

 of the tree will again be highly inflammable. The 

 amount of damage resulting to fire-scerred merchantable 

 timber is directly proportional to the number of fire- 

 scarred trees, and to the depth of the scars. This 

 form of damage is usually inconspicuous, yet is it con- 

 stant and inevitable, and considerable, because the 

 largest and most valuable trees are lost. It is only 

 rarely that non-fire-scarred trees are burned by a 

 single fire. 



Examples of Loss Occurring t hru the Burning Down 

 of Previously Fire-scarred Trees 



I, Forest Examiner S. B. Show in 1918, made a study of 

 five typical large fires in northern California, cov- 

 ering an area of 11,836 acres. He found that fire- 



