The Miner’s Bellows ([Pl. XI], Fig. 8). A leather bag with wooden top and bottom, provided with inlet and outlet valves, from the latter of which the air is led off in pipes or hose. In using the bellows the miner stands upon the lower handles and works the bellows with his hands by the upper ones.
This is frequently replaced by a common blacksmith’s bellows or the rotary blower from a portable forge; and sometimes by an improvised air-pump, consisting of a large open cask filled with water and another smaller one, with one head removed and the other provided with outlet and inlet valves and an air-tube, inverted over the large cask, supported by a spring-pole and worked up and down by hand in the water of the lower cask.
The Miner’s Candlestick ([Pl. XI], Fig. 9), which holds a candle, and may be driven into the side or bottom of a gallery.
Miner’s Lamps ([Pl. XI], Fig. 10), can be used only when the ventilation is good, as they give off more smoke than candles.
When an electric-light plant is available, incandescent lamps will be used for mining.
Earth Augers, similar to those used for boring post-holes, but of different diameters, are sometimes used for placing camouflets. Their shanks are made in short lengths, which can be joined together to allow of boring a deep hole from a narrow shaft or gallery.
GALLERIES AND SHAFTS.
19. The Dimensions of Galleries and Shafts are determined by the use to be made of them, the necessity of ventilation, and the minimum space in which a man can work.
They are usually about as follows, viz.:
| Height, feet. | Width, feet. | |
|---|---|---|
| 1. Great or grand galleries | 6 | 7 |
| 2. Common galleries | 6 | 3½ |
| 3. Half galleries | 4½ | 3 |
| 4. Branches | 3½ | 2½ |
| 5. Small branches (rameaux de combat). | 2½ | 2 |