Forest Fires. 155 



to fences, bridges, buildings, farms and mill property, and to cord- 

 wood, lumber and bark cut in readiness for market. Not only this, 

 they sterilize the land by burning out the vegetable mold, so that 

 trees can not be made to grow again, until in N>me degree this ma- 

 terial is restored by the decayed herbage, and the fall of leaves from 

 an undergrowth of bushes a process which requires many years 

 to accomplish. 



620. Sometimes the fire runs from tree to tree in the tops, instead 

 of spreading along the ground, as in the great Miramarhi fire of 

 New Brunswick, iu 1825, and the I'c.shtigo lire of Wisconsin, in 

 1871. Upon each of these occasions, many hundred human lives 

 were lost. The Michigan fires of 1M71 and INN! were memorable 

 from the destruction of towns, villages, bridges, and farm property 

 that they occasioned. 



<>21. In the great fires above mentioned, the forests had been 

 long exposed to intense solar heat and to drouth, and vegetable, 

 matter in every form would ignite from the least spark, and burn 

 beyond control. The currents of air which the llames excited, be- 

 came furious gales of wind, and swept every thing before them in a 

 tornado of fire. 



622. Without giving historical or statistical details, we will pre- 

 sent the subjects under the three heads of causes, prevention and 

 control. 



(1.) Causes of Forest Fir>.<. 



623. These fires generally originate from the following causes, 

 and somewhat in order of importance as here placed : 



(a.) From fires that escape in the clearing of lands, and the burn- 

 ing oft* of brush and stubble in preparing the ground for cultivation. 



(6.) From sparks and coals of locomotives along lines of railroad. 



(c.) From fires purposely set to improve pasturage, upon moun- 

 tains and in marshy grounds. This is a very common practice in 

 the Southwestern and Southern States, the fires being often set by 

 persons who do not own the land, to afford grazing to their few 

 head of cattle, upon lands not their own. 



(d.) From fires carelessly left by persons camping, hunting or 

 fishing, and by tramps. 



(e.) From the careless use of matches, that are thrown down and 

 not extinguished, or from tobacco-pipes, cigars, or gun-wads. 



