110 FIKST BOOK OF FORESTRY 



walks and begins to run even in the tops of the trees, as 

 well as on the ground, real fighting conies to au end and 

 only a " back fire " is of any use. 



A back fire is a line of fire set by the men to meet the 

 main fire. Thus, if the main fire travels eastward and 

 has a front of three hundred yards, the men run on ahead 

 to eastward and start a line of fires, so that the main fire 

 along this line finds most of the material consumed and 

 thus loses its force, and in favorable cases is stopped 

 entirely. Such a back fire should be started a good dis- 

 tance from the main fire, often half a mile or more away, 

 along some road, trail, creek, or raked fire line or trench. 

 The men watch the back fire to keep it from crossing 

 their line. If it is to succeed, the back fire should have a 

 good start, and burn fifty yards or more before it meets 

 the main fire. Trenching for the back fire is best done 

 early, as soon as daylight ; the fire had better be started 

 later, so that it will burn lively at once. 



" An ounce of prevention is worth a pound of cure " is 

 an old saying and applies to the forest fire. 



Wherever settlement has opened large fields or clearings 

 between tracts of forest and thus divides the woods into 

 well-separated blocks, serious forest fires no longer need 

 be feared. 



Even a moderate amount of such clearing, together 

 with the network of roads, has helped to protect the 

 pineries of the South ; and in New Jersey the opening of 



