162 Third Annual Keport of the 



accompanying ground or surface fires. Anyone of these classes of 

 fire, if burning vigorously, is likely to jump the fire line unless 

 backfires are set. In the case of ground or surface fires, these 

 back fires need burn over only a narrow strip before they meet the 

 main body of the fire. These fires do not acquire the momentum 

 of a crown fire. In the case of a fire of the latter class, back fires 

 must be set at a considerable distance from the main body of the 

 fire, in order that a wide strip may be cleared of fuel and the 

 crown fire checked before it approaches near to the fire line. 

 Otherwise the line will be crossed and the work will have to be 

 repeated on a new line of attack. 



The utmost caution must he observed in the use of back-fires. 

 They should not be set except when, in the judgment of an experi- 

 enced fire-fighter, they are absolutely necessary. Back-fires set 

 indiscriminately and by persons ignorant of their proper use, have 

 done untold damage because of their having been started miles 

 away from the main body of the fire by irresponsible persons, who 

 saw the smoke of the fire and thought that their property was 

 threatened. 



Back firing cannot be employed advantageously under adverse 

 wind or weather conditions. A large fire creates a draught of its 

 own, and this is one reason why a large forest fire is usually 

 accompanied by a strong wind, which fans the flames and carries 

 them along with it. The back-fire must be started far enough 

 from the main fire to escape the influence of this draught, and it 

 should be set where it will burn up hill, or it will do more harm 

 than good. When it is started, the greater part of the fire fighting 

 crew should be present to keep it from crossing the fire line. 



Patrol After Tire is Under Control 



Too much stress cannot be laid on the necessity of carefully 

 watching a fire until every vestige of it has been extinguished. A 

 large proportion of the damage which has been done by forest fires 

 has been caused by fires which have broken out after they were 

 believed to be controlled. A safe rule is to leave a man on a fire 

 until it is apparently out and, then have him stay a day or so 

 longer. The expense of this patrol will be amply justified in the 

 long run. 



