150 A MANUAL OF FORESTRY 



to be cleared, and whether the line is plowed, burned over, or 

 raked. Under the best conditions a ten to fifteen-foot line can- 

 not be constructed for less than $10 per mile, while in less favor- 

 able places the cost may easily run up to $50 or $75 per mile. 

 After it is constructed the cost of maintenance should be below 

 $10 per mile per annum. 



The location of fire lines is largely controlled by natural condi- 



By permission of the U. S. Forest Srrrire. 



Fig. 54. Fire line cleared through a hardwood stand. The line has not been properly 

 maintained and is covered with a thick growth of weeds. The fire hazard is now gn-aU-r 

 on the line than in the forest. 



tions. It is well to take advantage of brook beds which form a 

 barrier in themselves and where water can be obtained for 

 fighting fires; also of roads and trails; and especially of ridge 

 tops. Fires burn downhill very slowly and can, therefore, be 

 most easily checked at the top of a ridge. 



