36 ON THE FIRE-DAMP OF COAL-MINES', 



have now to explain, will be found, I trust, possessed of these 

 advantages. 



The facts on which it is in a great measure founded, are,, 

 that the inflammable gas accumulates in the roof of the mine, 

 — that it is fired, in the usual mode of lighting, before the mix- 

 ture of it with the atmospheric air fills the mine, or that part 

 of it in which the accumulation is taking place, — and that it 

 cannot fill it while the mine is worked, as the respiration of the 

 workmen would be previously affected. The miner works, 

 with his candle or lamp at a certain elevation, occasionally mo- 

 ving with it j and thus when the fire-damp has accumulated so 

 far as to fill a considerable part of the roof, the accidental ap- 

 proach of the lamp, or some concussion throwing the gas- 

 down wards, so as to bring it into contact with the flame, sets 

 it on fire. In one of the explosions, for example, within these 

 two years, that of the Hall Pit near Sunderland, in which thir- 

 ty-two men were killed, the explosion was supposed to have- 

 been occasioned by the fall of a stone from the roof, which car- 

 ried the inflammable air with it, so as to bring it into contact 

 with the pitmens' candles ; and this circumstance of a flake or 

 mass falling from the roof, and throwing the inflammable air 

 before it to the candles, has been often assigned as a cause of 

 these explosions. It is a proof of what is indeed sufficiently 

 established, the accumulation of the inflammable gas in the 

 roof of the mine. 



The method, therefore, which I would propose is, to bring 

 the supply of air to sustain the combustion of the lamp from 

 the floor of the mine. This may be easily done by burning 

 the lamp within a glass-case, having a small aperture at the 

 top to admit of the escape of the heated air and smoke, and 

 having attached to. the under part of it a tube reaching to the 

 floor of the mine to convey the -air. Figure 1st, Plate I. re- 

 presents this in a fixed lamp. 



One 



