CRANE. | Developing Mineral Properties. 203 
Methods of Blasting. 
The placing and firing of charges of explosive is one of the 
most important operations in mining proper. 
Under ‘‘ Methods of Shaft Sinking”’ is a full description of 
the methods of preparing a receptacle or hole for the charge. 
The placing of the charge will now be considered. Sticks of 
powder (dynamite) are either cut up into small pieces, or the 
paper covering is slit from end to end on all four sides. This 
is to allow the stick to crush up and fill the hole or recep- 
tacle. The dynamite is pushed into the hole by a wooden 
tamping rod, or by a spoon, and forced into the squibbed 
cavity at the end and tamped. A portion of the stick, about 
one-third of the length, is taken as a seat for the cap or 
primer, which is called a starter or primer.* In one end of 
the starter a cavity or hole is formed by a smoothly sharp- 
ened stick, in which is placed a cap or primer and fuse. The 
primer is slipped onto the end of a piece of fuse, and is 
crimped down tight upon the fuse either by means of the 
teeth or a pair of pincers, made especially for that purpose. 
This is to prevent any moisture from entering thecap. The 
end of the fuse bearing the primer is then introduced into the 
cavity made in the end of the starter. The paper which 
forms the covering for the dynamite is then gathered about 
the fuse above the cap or primer, and is tied with a strong 
cord. Under ordinary conditions this treatment protects the 
cap from moisture, but when considerable water is present 
greater precaution is necessary. A piece of fuse is ignited 
and the tar with which the fuse is covered, being heated 
up by the burning, is rubbed over the junction of the cap 
and fuse, thus healing up any little openings which might 
still remain. Grease or miners’ soap (soft soap) is also often 
rubbed over that portion of the starter which is tied to the 
fuse. The starter is then pushed into the hole until it rests 
upon the untamped charge below. Dirtis then thrown into 
the hole and tamped around and over the starter and charge. 
To prevent the charge from partially exhausting itself by 
*There is some confusion in the use of the terms starter and primer. Primer refers to the 
metal cap placed on the end of the fuse and not to the stick of dynamite. Starter would be 
more appropriately used in connection with the stick of dynamite in which the primer is placed. 
Primers may also be fired by electricity. 
14—Viii 
