60 FORESTRY 



to be protected is quite valuable as for instance, planta- 

 tions of young pine. It is not safe to trust to the ability 

 of a patrol service to be on hand with sufficient force to 

 stop fires. Here artificial fire-breaks should be constructed, 

 not so much with the idea that fire cannot cross them, 

 as to give the rangers the best possible chance to set 

 back fires and control the oncoming fire. Most of the 

 mistakes in building fire-breaks have arisen either from 

 the supposition that the fire-break must be wide enough 

 to prevent fires from crossing or in forgetting that such 

 fire-breaks, once constructed, do not stay clean, but grow 

 up to inflammable grass and brush if not tended. Fire- 

 breaks should be wide enough to check an ordinary fire, 

 and to make it safe to set a back fire against a fire travel- 

 ing on a strong wind. But a wind will blow a fire across 

 almost any fire-break in the absence of a back fire, hence 

 the absurdity of constructing very wide lines. In sandy 

 lands, lines may often be plowed, and a fifty foot wide 

 fire-line is more than sufficient. In most conditions, a 

 break as wide as this not only means great expense in 

 clearing, but the line soon becomes a jumble of briars 

 and young growth and ceases to be a barrier to fire. In 

 such cases, if old timber is standing the line should be 

 run through the timber and consist of a well-cleared strip, 

 perhaps not over ten feet wide under the crowns of the 

 old trees, which will keep down the young growth that 

 would otherwise spring up. The main point is to clear 

 the ground of leaf litter, dead logs and brush, and ex- 

 pose the mineral soil. In many places strips 3 or 4 feet 

 wide, literally paths, serve the purpose of fire-breaks. 

 Such lines have been constructed in southern pine re- 

 gions to check the small annual grass fires that destroy 

 the seedlings. The most difficult problems are in regions 

 like the Adirondacks where a fire-line is not complete with- 

 out a trench dug through the accumulated duff down to 

 soil one or two feet below. Such lines have often had to be 



B III 13 



