446 THE HANDBOOK FOE PEACTICAL FARMEKS 



dynamite. If detonators were to explode by themselves, they 

 would not be likely to do much damage unless there were a great 

 many of them, but if they were to explode in the same room with 

 dynamite, they would probably cause the dynamite to explode. 



Opening cases. — When ready to use the dynamite, open the 

 box or case with a hardwood wedge and a mallet. Never take 

 more than the day's supply to work, even in warm weather. 

 In cold weather, take only as much as can be kept thawed until 

 it is to be used, unless there are arrangements for keeping it 

 thawed where the blasting is to be done. 



Blasting. — When dynamite or other high explosives detonate, 

 the small volume of solid is converted immediately into a volume 

 of gas many times greater than the solid. If the explosive is 

 unconiined there is a great pressure exerted on the holding 

 material, which if not too strong, will be shattered or blown 

 away. 



The force of the gases is equal in all directions. If the desire 

 is to blow a boulder or stump into the air the charge is placed 

 below the object. The best shattering is obtained if the explosive 

 is placed in the material to be broken so that the force is exerted 

 on it equally in all directions. This is applicable in blasting 

 soils and blockholing boulders or in splitting stumps. 



While the gases exert an equal pressure in all directions, they 

 try to escape by the easiest route or along the line of greatest 

 weakness. If the tamping is omitted or is insufficient, the ten- 

 dency will be to blow out through the bore hole. If a hole is 

 placed to the side of a stump, the tendency will be to blow out 

 through the more easily lifted soil. The aim should always be 

 to make the easiest way out directly through the material to be 

 moved or shattered. 



Detonation. — As has already been explained dynamite is fired 

 or ''detonated" by means of the shock from a blasting cap or 

 electric blasting cap, either of which is known as a detonator. 



In order that the detonation may be complete, or, in other 

 words, that the full strength of the explosives be developed, the 

 detonator should be placed inside the charge, with its closed or 

 ''business end" pointed toward the main bulk of the charge. 



Priming tvitJi cap and fuse. — The act of placing the detonator 

 in the charge is known as "priming" and the cartridge of ex- 

 plosive with the detonator in it is called a "primer." 



Attaching the Masting cap to fuse. — Examine your dynamite 

 and see that it is not frozen. Frozen dynamite is hard and 

 rigid, and dangerous to handle; when thawed it is soft. Next 



