15 ^ 
I am not prepared to say that the employment of gun- 
powder should be forbidden, or that a seam which cannot 
be profitably worked without it should be abandoned. But 
I do think that the difference in cost between gunpowder and 
the pick alone should be considerable, to render blasting, on 
the whole, advantageous to the proprietor. That it forms of 
itself a naked light, and thus renders almost nugatory the 
use of lamps, is obvious. The sudden dislodgement of large 
masses of coal must favour sudden and rapid discharges of 
gas ; while the loose, open, shattered condition, which it is 
the very object of blasting to produce, is no less favourable 
to keeping up the emission. When the coal is cracked and 
crushed, the pillars or posts” left must either be larger, or 
they will be weaker, and not the coal alone, but the roof, will 
sufier, and those falls” of stone or shale take place which 
are the causes of fatal accidents in various ways, and explo- 
sions among the number. It is not, then, alone a question 
between so many pounds of gunpowder on one hand and so 
many weeks’ additional wages on the other ; the coal shaken 
by blasting is also less valuable, from the readiness with which 
it falls into “ slack.” 
Many considerations point to the goaf or wastes, or worked 
out portions of a mine, as the source and seat of explosions. 
The evidence, it is true, must be, from the nature and results 
of the calamity, inferential, rather than direct. What no 
living eye has witnessed, no living tongue can remain to tell. 
But in the Haswell Colliery, and in some other cases, satis- 
factory evidence as to where the gaseous mixture fired was 
afforded by the direction in which its force acted, and by the 
condition and situation in which the bodies of some of the 
pitmen were found ; and the goaf of thirteen acres was 
there indicated as the largest reservoir of gas. At Jarrow 
the waste was clearly pointed out. At Risca the evidence 
