Bombs Impractical For Fighting Forest Fires. 



Ingenious, imaginative persons have recently pro- 

 posed as a method of fighting forest fires that gas 

 bombs be dropped from airplanes. Officials of the For- 

 est Service, United States Department of Agriculture, 

 say that the suggestion is entirely impractical. There is 

 no analogy between the suggested method and the 

 use of poison gas bombs in fighting, because a fire 

 can not be "poisoned" but must be smothered. Al- 

 though one part of a poison gas to one million parts 

 of air might be sufficient to kill soldiers, yet 750,000 

 parts of inert gas to a million parts of air probably 

 would not suffice to put out a fire. 



The only kind of a gas which will assist in stopping 

 a fire, forest officials declare, is an inert gas that will 

 neither burn nor support combustion, such as nitrogen 

 or carbon dioxide. 



From the standpoint of cheapness and ease in hand- 

 ling, carbon dioxide would probably be the most 

 promising gas, were gas bombs to be experimented 

 with in forest fire fighting. However, as soon as ah 

 attempt is made to work out practical plans for such 

 an undertaking, difficulties become apparent. If an 

 airplane carrying 500 pounds of gas bombs containing 

 300 pounds of carbon dioxide succeeded in dropping 

 the bombs exactly 011 a fire covering some 700 square 

 feet, and if the gas liberated did not escape outside 

 this area or rise more than 10 feet above the ground, 

 still such an attack would be far from effective. The 

 300 pounds of gas would be equal, in volume, to about 

 3,000 cubic feet, and so the atmosphere surrounding - 

 the fire would be about 43 per cent carbon dioxide 



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