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Black blasting powder-
Opening kegs of powder.
Paper powder kegs.-
Danger from use of loose powder---
Explosive force of black blasting powder--
Black powder and dynamite---
Carrying and storing powder in mines_.
Placing and charging holes_--
Shooting off the solid..
Line of least resistance -
Size of drill hole.---
Regulating length of drill holes_
Poorly balanced shots..
A well-balanced shot----
Holes drilled into the solid..
Stuck cartridges ---
Tampers and needles_
Firing with squibs..
Firing with fuse..
Firing with electricity.
Electric firing with a hand battery-
Location of miners when shot is fired.-
Shot firing on the return air..
Firing shots in adjacent working places.-
Leaving black-powder cartridges open to the air..
Special shot firers------
Advantages of systematic firing-
Time for shot firing-
Duties of and necessity for shot firers
Precautions to be taken with black blasting powder.
Permissible or safety” explosives_
Classes of permissible explosives.---
Class 1, ammonium nitrate explosives..
Class 2, hydrated explosives_-
Class 3, organic-nitrate explosives--
Class 4, nitroglycerin explosives--
Cost of permissible explosives---
Care of permissible explosives.
Handling and storage of permissible explosives in mines.-
Force of permissible explosives---
Explosions of magazines---
Thawing frozen explosives.
Size of drill hole--
Firing a double charge of permissible explosive in the same hole---
Size of cartridges..
Placing the detonator.
Detonator should fit tightly in cartridge.
Imperfect detonation by using laced fuse_
Danger from powder and high explosives in the same hole_.
Loose charges should not be used--
Tampers and tamping--
Shots on the solid---
Blasting with permissible explosives..
Firing with detonating squibs_-
Firing with fuse_-
Blasting with electricity-
Defective insulation --
Dry-cell batteries without safety contact buttons..
Shooting from the trolley wire_-
Time for shot firing----
Special shot firers for permissible explosives..
Delay in returning after firing----
Precautions to be taken with permissible explosives_
Publications on mine accidents and methods of mining--
FIGURE 1. A hole with a dead end; a dangerous shot; and a properly
2. Plan view of a poorly balanced shot-
3. Plan view illustrating a safe method of shooting the shot
shown in figure 2----
4. A badly placed shot hole---
5. Cartridge with electric detonator in position..
6. Details of two adjacent shots fired at the same time with fatal
7. Arrangement of a double charge in the same hole, electric de-
tonators being used----
8. Arrangement of detonator wires for double charge_