VAPOURS, noxious, method of dissipating. The following ingenious method of dissipating the noxious vapours commonly found in wells and other subterranean places, is related in the Transl. Philadel. by Mr Robinson of Philadelphia the inventor. "After various unsuccessful trials (says he), I was led to consider how I could convey a large quantity of fresh air from the top to the bottom of the well, supposing that the foul would necessarily give way to the pure air. With this view I procured a pair of smith's bellows, fixed in a wooden frame, so as to work in the same manner as at the forge. This apparatus being placed at the edge of the well, one end of a leather tube (the hose of a fire-engine) was closely adapted to the nose of the bellows, and the other
end was thrown into the well, reaching within one foot of the bottom. At this time the well was so infected, that a candle would not burn at a short distance from the top; but, after blowing with my bellows only half an hour, the candle burned bright at the bottom; then, without farther difficulty, I proceeded in the work, and finished my well. Wells are often made in a very slight manner, owing to the difficulty of working in them, and there have been several fatal instances of the danger attending the workmen; but, by the above method, there is neither difficulty nor danger in completing the work with the utmost solidity. It is obvious, that in cleaning vaults, and working in any other subterranean place, subject to damps as they are called, the same method must be attended with the same beneficial effect."