Charging 



Having primed the cartridge in the manner described, insert it in 

 the borehole on top or next to top of the rest of the charge if more than 

 one cartridge is used and push it carefully home. Putting the explosive 

 into the borehole is called charging or loading the borehole. It is 

 generally best in dry ground to slit the paper shells lengthwise in two or 

 three places with a sharp knife before putting the cartridge into the 

 borehole, as a slit cartridge will spread out in the borehole better. The 

 primer should not be slit. Push the cartridges, except the primer 

 cartridge, firmly into place with a wooden stick so that they will expand 

 and fill up their part of the hole, for crevices or air spaces may lessen 

 the power of an explosive. Expanded cartridges also occupy less of the 

 length of the borehole and make possible a heavy charge at bottom of 

 hole. The primer is loaded last, or next to last, and is pushed down only 

 hard enough to touch the preceding cartridge. Each cartridge must 

 touch the one previously loaded, for if any space between the cartridge 

 occurs through falling dirt or stones, or through the sticking of a 

 cartridge in the borehole, a part of the charge may fail to explode. 



Never force a primer into a borehole, because the detonator which it 

 contains is sensitive to shock and might explode if too much force is used. 



Tamping 



After the charge is pressed home, as directed, put in two or three 

 inches of fine dirt or damp sand, and with a wooden stick press it gently 

 on top of the dynamite. Then fill up two or three inches more of the hole, 

 packing it in a little more firmly. After five or six inches covers the 

 charge, it may be pressed firmly into place without danger of premature 

 explosion. The tamping material should be packed as firmly on top of 

 the charge as can be done without moving the electric fuze or blasting- 

 cap in the primer, but it is not safe to tamp by a blow any stronger than 

 can be given by hand. Fill the borehole up with 'tamping until even with 

 the surface. The firmer and harder the tamping can be made (without 

 overlooking the above precautions) the better will be the results. If the 

 borehole is not properly tamped, the charge is likely to " blow out," or 

 at any rate some of its force will be wasted. 



Do not use iron or steel bars or tools for tamping because the metal 

 tools may detonate the explosives. Use only a wooden tamping stick 

 with no metal parts. 



FIG. no. HOME MADE TAMPING STICK 



122 



