PROTECTION AGAINST FOREST FIRES. 241 



line of fire, which thus makes headway against the direction of 

 the breeze. 



Every ground-fire that breaks out in a coppice-wood finally 

 develops into a crown-fire if it be of large extent, for whenever it 

 eats its way into thickets and pole-forests it runs up into the 

 crowns, and then the danger is much greater, whilst extinctive 

 measures are far more difficult and troublesome, especially during 

 high wind, when the smoke, flames, and heat are driven on 

 ahead. The conflagration may then assume such proportions that 

 extinctive measures are no longer practically adoptable ; such fires 

 may rage till they are stopped by some natural occurrence or 

 adventitious circumstance happening to check them, as, for 

 instance, a broad stretch of unplanted clearance, or a belt of 

 broad-leaved trees, or the reaching of the extreme limits of the 

 woods. 



Broad fire-protection paths, planted up with non-coniferous 

 species of trees bearing a good crown of leafy foliage, are the 

 best means of preventing the spread of conflagrations, and are, 

 owing to the interruption of the coniferous canopy, the only sure 

 basis upon which extinctive measures can be soundly adopted. 

 This interruption of the canopy afforded by narrow interior lines 

 can be materially assisted by rapidly clearing away a belt of trees 

 along the further side, and working thus to join one of the main 

 fire lines. But in this work, as well as in quickly removing any 

 inflammable matter from the ground in the case of ground-fires, 

 care must of course be taken to begin operations so far ahead of 

 the fire as to ensure their completion before the fire has had time 

 to come up to the lines. Poles and trees, which it may have been 

 found advisable to fell, should be lopped of their branches, and 

 these should be removed so far into the further side of the woods 

 as to render it improbable that they will catch fire from the 

 sparks. 



In crown-fires, too, which have already caught firm hold on 

 thickets and young pole-forest to any considerable extent, the leaf- 

 canopy should be interrupted in as broad a belt as possible by 

 firing the woods along the edge of one of the fire-protection lines 

 or interior paths. Great prudence is of course necessary in doing 

 so, in order to prevent the fire spreading into the crops lying 

 behind the line ; but when these are of older growth less danger 

 is in this respect to be apprehended, and the chief attention will 



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