MINING. lil 
rock which he wishes to obtain, and smites the face of the pick with a 
short-handled two-faced hammer or mallet (pl. 23, jigs. 20 and 21). The 
miner has a selection of different kinds of picks, adapted to different kinds 
of rock. These he arranges on a piece of an iron ring curved like a hook, 
or has a shap or chain (pl. 23, jig. 18) with two pieces of hoop iron. Since 
the employment of powder, the hammer and pick have been used in hard rock 
only for levelling and digging holes, or where timber-work and machines 
prevent the use of powder. ‘The mining pick is more useful for working in 
veins of ore, where also crowbars and large-sized steel wedges (jig. 29, a 
and 6) for driving into the fissures of the rock are used. 
The use of powder for mining began about the year 1613, and produced 
an entire change in the mining operations carried on upon solid rock. The 
first operation in blasting with powder is the drilling of a narrow cylindrical 
hole, a (fig. 9), in the mass to be blasted off. This hole is partiy filled with 
gunpowder, and then, with the exception of a narrow channel needed for 
firing it off, is rammed down hard, so that the powder which is in the hole 
on being ignited must exert its force on the rock which surrounds it. Pl. 
24, fig. 40, exhibits a miner busied in the labor of drilling. The holes 
drilled are from 10 to 48 inches deep, and about half an inch wide. The 
drill used for boring the cylindrical hole is usually a round iron rod, which 
ends in a steeled and hardened chisel or cutter (pl. 28, jigs. 22a and 6). The 
drill is held in the left hand, and is driven by a hammer. The drill should 
be occasionally immersed in water to prevent the flying of dust from the 
hole, and to prevent it from losing its temper by being heated. 
In the mines of mineral salt at Northwich, Cheshire, England, they 
use a drill seven or eight feet long, consisting of an iron rod which 
bellies in the centre. This drill is held by the middle (pl. 23, jig. 12). 
In quarrying gypsum in the vicinity of Paris, they bore with a kind 
of auger (jig. 26). In mining brown coal in Lankowitz, in Carinthia, 
they make use of an auger (jig. 35), provided with a handle like that of a 
bitt stock, having a flat lance-shaped pod with a small point, the steeled 
edges of the cutting-tool being slightly twisted. For boring a hole with 
this instrument three feet, and charging and firing the blast, an hour is 
sufficient. 
After the hole has been freed from the dust and chips by the scraper 
(jig. 23), a dry wad of tow is put on the lower side of the scraper, which 
absorbs the water in the hole. The hole, when dry, is charged with from 
two ounces to one pound of powder, wrapped in a cartridge of paper or 
tarred linen, or if the hole is under water, placed in a well closed leaden or 
tin cylinder. The cartridge is driven in by means of a rammer (jig. 24), 
which is made of wood, copper, or iron. Previously, however, the priming- 
rod (jig. 25) has been stuck into the cartridge and is introduced with it 
into the hole. The priming-rod is of copper, and reaches only half way 
into the powder in the cartridge. The space above the cartridge in the hole 
is filled with clay, pieces of brick, or pounded slate-stone. This is called 
the tamping. The first inch or two of the tamping above the cartridge must 
be only lightly rammed around the priming-rod, and the successive layers 
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