The famous salt mines at Wieliczka have been worked since the Middle Ages. Here, miners are lowered down the shaft on a rope, each carrying a candle. Accidents were frequent: naked flames could ignite gas causing explosions; cave-ins trapped miners under tons of rubble, and underground flooding drowned many more. Despite modern technical improvements and stricter health and safety regulations, mining remains a dangerous occupation. Illustration from 'Underground life, or, Mines and miners' by Louis Simonin (1830-1886), published in London in 1869.
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