466 
COAL. 
time without doing any mischief; but when, by 
some accident, they are set on fire, they produce 
dreadful and destructive explosions, and burst out 
of the pits with great impetuosity, like the fiery 
eruptions from burning mountains. 
“ The coal in these mines hath several times 
been set on fire by the fulminating damp, and con- 
tinued burning many months, until large streams 
of water were conducted into the mines, and suf- 
fered to fill those parts where the coal was on fire. 
Several collieries have been entirely destroyed by 
such fires : of these there are instances near New- 
castle, and in other parts of England, and in the 
shire of Fife in Scotland ; in some of which places 
the fire has continued burning for ages. To pre- 
vent as much as possible the collieries from being 
filled with these pernicious damps, it has been 
found necessary to search for those crevices in the 
coal whence they issue, and then confine them 
within a narrow space, from which they are after- 
wards conducted through long tubes into the open 
air, where, being set on fire, they consume in per- 
petual flames, as they continually arise out of the 
earth. The late Mr. Spedding, who was the great 
engineer of those works, having observed that the 
fulminating damp could only be kindled by flame, 
and was not liable to be set on fire by red-hot iron, 
nor by the sparks produced by the collision of flint 
and steel, invented a machine, in which, while a 
steel wheel is turned round with a very rapid 
motion, flints are applied to it, and by the abun- 
