700 JOURNAL OF FORESTRY 



Fire lines, natural or constructed, should occur at not over half-mile intervals, 

 and the area of continuous slash should not be more than i6o acres, or be five- 

 eighths of a mile in any one direction. 



By utilizing natural features, it is expected that the mileage of standard fire 

 lines, whose construction is necessary to give this degree of protection, will not 

 exceed four miles per section and may be less. 



Fire lines should usually follow all railroad spurs, except when these are lo- 

 cated at intervals smaller than required by the standard, and should always be 

 constructed along main traveled wagon roads. 



The location of fire lines should avoid low crowned conifers and coniferous 

 reproduction. If this is impossible, it is better to destroy these crowns by burn- 

 ing on the fire line. 



Wide fire lines on ridges with sparse growth are preferable to narrower lines 

 in the bottoms of draws with excessive brush disposal. 



The following departures from this standard will be permitted : 



1. In yellow pine, where slash is not heavy, areas of 320 acres may be ac- 

 cepted as a maximum, provided fire lines occur at half-mile intervals, cutting ap- 

 proximately at right angles to the direction of prevailing dangerous winds. 



2. In Douglas fir, areas of 80 acres may be required as a maximum, especially 

 when the stand per acre is heavy, justifying increased cost per acre for fire lines. 



Comments on Brush Disposal in the Southwestern District 



By G. A. Pearson 



The difficulties of burning large areas of piled brush are recognized. 

 I believe, however, that if it were found otherwise desirable to pile and 

 burn, this difficulty could be overcome. 



In pulling tops the greatest difficulty is, as pointed out in the standard 

 instructions of District 3, the complexities which render it almost im- 

 possible in practice to get the work done properly. Conditions on most 

 areas vary to such an extent that good results cannot be secured unless 

 a forest officer personally directs the work. As a rule, the tops are not 

 pulled far enough away from living trees. The tendency is to mass a 

 great number of tops in the openings, where in case of fire they would 

 destrov all living trees on the leeward side within 50 feet. I have seen 

 numerous instances of this condition on cuttings on the Coconino For- 

 est. Tops left intact, especially if there are several in a group, un- 

 doubtedly make a hotter local fire and throw the flames higher than is 

 the case where the brush is scattered more or less evenly over a larger 

 area. If the tops are placed at a safe distance, all well and good; 

 otherwise they are a great menace. 



There has been much discussion of the protective influence of brush, 

 both when scattered and when the tops are left intact. When the tops 

 are left intact, there is apt to be such a heavy accumulation of litter 



