272 LOGGING 



Dynamite which is rather soft resembles brown sugar. It 

 is packed in paraffine- coated paper shells or cartridges, the 

 standard size being i j by 8 inches and containing one-half pound. 

 Other sizes, from |-inch to 2 inches in diameter and 6 inches and 

 over in length are also manufactured. Dynamite cartridges are 

 packed in sawdust in wooden boxes containing 25 or 50 pounds 

 each. 



Dynamite freezes between 35 and 50 degrees Fahrenheit and 

 when frozen must be thawed before use. Thawing kettles which 

 are best for this work consist of a double galvanized iron bucket 

 having an inner water-tight receptacle for dynamite and an outer 

 receptacle for warm water which must not exceed 100 degrees 

 Fahrenheit, otherwise the nitro-glycerine may separate from the 

 absorbent. Cartridges are sometimes spread out on a shelf in a 

 warm room and left during the night but should never be thawed 

 in an oven, near a fire or placed against a stove or steam pipe. 

 A few cartridges can be easily thawed out by placing them flat 

 in a water-tight box and burying them in fresh manure. 



Great care must be taken to prevent the dynamite from coming 

 into contact with moisture, because water has a greater affinity 

 for the absorbent than has nitro-glycerine, and the latter will be 

 driven out; on low grades of dynamite the salts of the auxiliary 

 explosives are also expelled. 



Dynamite with a high percentage of nitro-glycerine de- 

 teriorates during warm weather, when stored in a warm place, or 

 if kept for long periods. Chemical decomposition takes place, 

 liberating nitrous fumes which often are the cause of violent 

 explosions. A greenish color on the cartridges is a certain in- 

 dication of chemical decomposition, and handling dynamite in 

 such condition is always dangerous. 



Nitro-glycerine from the cartridge may be absorbed through 

 the hands, and men who handle d>Tiamite are subject to severe 

 headaches. This may be obviated partially by wearing gloves 

 which should be thrown away as soon as they become saturated. 



Loading Holes. — The charge should completely fill the bore 

 hole because explosives exert the greatest disruptive force when 

 there are no air spaces below the tamping. 



