Firedamp

• In the early days of mining, most mine shaft explosions were caused by the ignition of pockets of naturally occurring gases called firedamp. Initially, little chance existed for a firedamp explosion because the gas only becomes flammable when a certain proportion of oxygen is present. The poorly ventilated mines of the late 18th century did not contain enough air to cause an explosion, but as the size of mine shafts began to increase, so too did the dangers involved in using an open flame underground.
  
  

Early Lamps

• The first lamps miners used were small candles set into lumps of clay. A miner could control the size of his candle's flame by molding the clay in front of the wick higher to decrease the amount of air exposed to the flame. When entering a shaft, the miner would slowly raise his candle from the floor with one hand extended, palm out, to block all but the tip of the flame from his vision. If the tip began to glow blue, indicating the presence of gas, the miner would retreat from the shaft until the gas was cleared.
  
  

Safety Lamps

• With the possibility of an explosion always an imminent threat to mine workers, the need for safer lamp technology had become apparent. Sir Humphry Davy created one of the first safety lamps when he invented his Davy Lamp in 1815. Using a thin metal gauze to surround the flame, Davy calculated that the mesh would cool the flame before it could ignite any firedamp, which would extinguish any flame that wasn't hot enough to ignite the substance.
  
  

Electric Lamps

• Advancements in safer fire-burning lamps continued to be made throughout the 19th century, and culminated in the invention of the electric lamp in 1902. Early electric lamps required miners to carry cumbersome batteries that often leaked acid. Today, miners use small cap lamps and parabolic reflectors equipped with specially designed safety features. Today's lamps allow miners to freely work in any position without interference or the threat of igniting any trapped firedamp deposits. However, explosions from other causes continue to claim the lives of miners.