Mining Methods in the Lead-belt and Madison County
by Jack Ward Skinner
The original mining was on the surface. Then, that surface was quarried out as it was found that the ore extended down below the surface. In the early days, a few mines were dug back into the side of a hill or mountain, following a vein of ore. Some were productive, others were hit or miss.
Then came the drill rigs. Especially, the diamond drills. They would bring the core samples to the surface, and the mining engineers could then map out just what direction, and how far down, the veins were located.
To give you an illustration (kids! Do not do this, because it surely ruins a good loaf of bread.)
Empty a full loaf of bread. Put 2-3 slices back into the wrapper. On that 3rd slice, smear some peanut butter in a random order. Put a few more slice of bread back, smearing the last piece again with peanut butter. Keep doing this until you have all the bread back in the wrapper. Us something stiff, like an old curtain rod that is hollow. Push it down through the loaf of bread, twist it a couple of times, then withdraw it from the loaf. Use a small dowel rod and push it down through the center of the curtain rod, pushing the bread on the inside, out the other end. Ever so often, in the plug of bread, you can see a trace of peanut butter.
The bread represents the layers of sedimentary rock, mainly limestone, in this part of the country. The peanut butter represents a layer of galena (lead) or some other mineral ore. By measuring the length of bread plug from the top to the different layers of peanut butter, one would know how far to sink a shaft to find the “lead”. This takes a lot of the guess work out of mining underground. Even newer methods can be used to day, such as seismic readings.
Once the shaft has been sunk to the level of a vein of ore, then horizontal drilling and mining begins. These are called drifts.
Sometimes the veins are thick and may branch out in several directions. As more and more of the rock is mined, the cavern gets larger and larger. The ceiling (also referred to as the Back), extends farther and farther. It needs to have support to keep it from caving in. So, engineers calculated where support is needed and they will leave a column of rock, called a pillar. This acts similar to a post on a front porch. If there are different levels of drifts, one under another, these pillars are usually left vertically in line, so the support continues to the bottom of the mine.
In the above picture, you can see an underground mine that has had a large part of rock and ore removed. In the center is a pillar. I do not know which mine this was shown, but it is typical of the underground mines all through this area. It’s an old picture on hard, cardboard backing. If you look closely, you might see that the lights on the miner’s helmets are carbide lamps. These lights consisted of a base where water and carbide were mixed, producing a gas. The gas could be released through a large reflector. The gas was ignited and gave off enough light for the miner to see in a pitch-black world that he worked in. In later years, a battery powered, electric light was used.