AND PREVENTING ITS EXPLOSION. 35 
and walls, the sides of the passages gradually approach, form- 
ing what the miners calla creep ; sometimes, too, the stoppings 
and trap-doors which direct the current of air through the pas- 
sages, are neglected, the ventilation is either partially stopt, or 
is impeded, the fire-damp gradually accumulates, and ming- 
ling with the air, forms a mixture which is capable of explo- 
ding. There is reason to believe, too, that in some cases, the 
accident has arisen from the sudden discharge of the gas from 
fissures in the strata, or from the opening of a cavity in the 
mass of coal in which it had been confined ; it often takes fire 
at the candles of the miners, when discharged in this way ; is 
sometimes discharged in large quantity with the greatest vio- 
lence ; and if intermingled with a rapid current of atmosphe- 
ric air, the inflammation may increase in rapidity to an explo- 
sion. 
It is obvious, that attention to these circumstances is of the 
first importance ; and, so far as improvements in the system of 
the mines in that respect are practicable, their propriety can- 
not be questioned. As it appears, however, that there are some 
causes which ‘can scarcely be effectually obviated, and as the 
utmost attention which can reasonably be expected, seems, un-» 
der the circumstances of the mines, and the constant genera- 
tion of the enormous quantities of gas which they yield, to be 
insufficient for perfect security, the importance becomes evi- 
dent, of some mode of lighting being devised, which should 
guard against the firing from the large discharge, or eccasional 
accumulation of the inflammable air, while, at the same time, 
the danger should be indicated, so that the necessary means to 
remove it might be employed. 
No difficult or complicated method can be expected to suc- 
ceed. Any method to be successful, must be simple, easy of 
execution and of use, and not too expensive. That which I 
E2 have 
