In some mines the inflammable and poisonous gases are given off in such abundance by the coal that it is dangerous to remain in them for even an hour after ventilation has been stopped. At such collieries when, on account of accident, or for any reason, the fan stops running, the men are called out immediately, and are not allowed to enter again until a new circulating current has been established. One of the most notable mine disasters of recent years was caused by the quick accumulation of black damp and white damp in a mine, the ventilating system of which had been destroyed and the shaft burned out by fire. This was at Avondale, near Plymouth, in Luzerne County, Pennsylvania, on the 6th of September, 1869. There were three conditions here, the presence and coöperation of which made this calamity possible. First, the mine was ventilated by a furnace at the foot of the shaft; second, the breaker was built over the mouth of the shaft; and, third, the shaft was the only outlet from the mine. The partition of the ventilating flue took fire from the furnace draught. At ten o’clock in the forenoon a young man by the name of Palmer Steele stepped on the carriage with a load of hay to take to the inside stables. Half way down the shaft the hay took fire from the burning buntons. The engineer saw the flames rise from the mouth and let the carriage, with the young man on it, as quickly as possible to the bottom. There were then in the mine one hundred and eight men. Not one of them came out from it alive. In an incredibly short space of time the flames leaped to the top of the breaker, one hundred feet from the ground, and by the middle of the afternoon the great building was a mass of ruins, covering over and blocking up the only entrance to the mine. It was far into the night before the débris had been sufficiently cleared away to permit of descent into the shaft. Then two men, Thomas W. Williams and David Jones, went down to search for the imprisoned miners. They were scarcely beyond the foot of the shaft when they stumbled into a body of white damp and were stricken with death. The fire occurred on Monday. It was not until ten o’clock Tuesday morning that a sufficient ventilating current had been established to make it safe for men to descend. The greatest distance that it was possible to go from the foot of the shaft on Tuesday was seventy-five feet. Beyond that point the danger from suffocation was still imminent. Only three bodies had been thus far found.