One of the most characteristic disasters of recent times, resulting from the explosion of fire damp and the accumulation of after damp, occurred on Monday, August 14, 1871, at the Eagle Shaft, situated about a mile below the town of Pittston, in Luzerne County, Pennsylvania. At nine o’clock on the morning of that day a driver boy by the name of Martin Mangan was passing along an upper gangway, driving a mule with a trip of mine cars. Just above him lay a section of the mine that had been worked out and abandoned, in the old chambers of which a large body of fire damp had been allowed to accumulate. At the hour mentioned there came a sudden and extensive fall of roof in these old workings. The impulse given to the air by this fall drove it out into the working galleries, and with it the inflammable gas. When the fire damp reached the heading and touched the flame of Martin Mangan’s lighted lamp there was a terrific explosion. At the mouth of the shaft timbers were cracked, clouds of dust poured out, and débris from the mine was thrown violently into the outer air. People who were a mile away heard the noise of the explosion and hastened to the scene. Mining experts knew at once what had occurred. As soon as sufficient repairs could be made to the shaft a rescuing party, led by Superintendent Andrew Bryden of the Pennsylvania Coal Company’s mines, descended into the mine and began to search for victims. Those workmen who were on the other side of the shaft from where the explosion took place were rescued and brought out alive. But little progress could be made, however, toward the region of the trouble on account of the after damp which had accumulated. Up to two o’clock on Tuesday morning five dead bodies had been discovered, and during that day twelve more were taken out; all who had worked in that section of the mine. The positions of these bodies showed that the men had fallen where they chanced to be when the explosion occurred. The first wave of after damp that touched them had made them insensible, and death speedily followed. They died from asphyxia. “Black damp” is pure carbonic acid gas, containing two parts of oxygen to one of carbon. It is the principal constituent of after damp, which may, indeed, contain no other elements in appreciable quantities. The two mixtures are therefore often spoken of as being the same, and the miners apply the term “choke damp” indiscriminately to either.