When the naked light of the miner comes into contact with any considerable quantity of fire damp in an explosive state the shock that follows is terrific. Men and mules, cars and coal, are hurled together to destruction. Walls are swept out, iron rails are bent double, doors are torn from their fastenings, the mine is laid waste. The damage which results from an explosion of gas is of course much greater than that which is due to mere ignition and burning without the explosive force. In the latter case, however, the danger to the miner is but slightly diminished. He is liable to receive injuries which may prove immediately fatal. His burning lamp no sooner touches the body of fire damp than it bursts into flame, which, propelled by expansive force, passes swiftly down along the roof of the chamber. Taking up enough oxygen from the atmospheric air to make combustion more fierce, it returns to the face of the chamber with a violent contractile surge, scorching everything in its path, and then, perhaps after another brief sally, it burns itself out. The miner who accidentally fires a block of fire damp falls suddenly flat on his face on the floor of the mine, burying his mouth, nose, and eyes in the dirt to protect them from the flame and intense heat. Then he clasps his hands over the back of his head and neck to protect these parts from injury, and lies waiting for the minute or two to pass before the fire shall have burned itself out. But he must not wait too long. The fatal after damp follows quick upon the heels of the flame, and his only safety from certain death lies now in immediate flight.