1796.] 
This air is particularly dangerous, on 
account of its inflammable quality ; fince 
‘it inftantly takes fi‘e by the flame of a 
candle. Toavoid this accident, they have 
many machines, called flint-mills. Thefe 
are compofed of a fquare frame of iron, 
about fifteen inches long by eight broad: 
in it are fent [ fixed | two axes, on one of 
which is a toothed wheel, feven or eight 
inches diameter, which turns a pinion on 
the other, of the diameter of about an inch 
and a half. On the fame axis with the 
pinion, isa fmall wheel of fteel, four or 
five inches diameter, and very thin. By 
help of one of thefe mills, a man will give 
light to five or fix workmen. He fup- 
ports the machine againit his belly on one 
side, and againft fome fixed plece on the 
other: with one hand, he holds a flint 
[larger than a gun funi\ againft the edge 
ef the ficel wheel, and with the other 
turns a handle fixed to the axis of the 
large toothed-wheel, which turning in 
the pinion gives a very rapid motion to 
the fteel-wheel ; and this, by its friction 
againft the flint, fends forth a copious 
ftream of f{parks, 
This machine, though lefs dangerous 
¢han any contrivance hitherto known, is 
not, however, perfectly fecure 5 fince the 
{parks which it produces are capable of 
kindling the bad air [wen of a proper 
mixture of purc inflammable ar}. ‘There 
was a very recent inftance of this: at the 
time of the late accident, there was 
no fire cr light in the place, except 
what was produced by the ttecl mills. 
When there is no circulation, and the 
foul air ig too aBundant, the iparks give 
nolight atall. In this cate, the work- 
men quickly Jeave the place; otherwife 
they would probably periifh. They are 
fometimes extremely fick with it, and fall 
down feniele’s. They would undoubtedly 
perith by fuffocaticn, wx they were not 
quickly relieved by removal into the 
frefh air. 
To prevent fuch accidents, they always 
fet a number cf men to work in the fame 
place; and thefe have the precaution to 
call to each other every five or fix mi- 
nutes; notwithfanding which, there is 
not a week, that they. are not obliged to 
bring out fome of theminto the air, quite 
fenfelefs. 
this cafe, refembles that of an emetic, or 
a very irritating purge; it renders them 
fick for manyidays. )..°. 
When the foul air takes fire, the fureft 
way to avoid being killed, is, when they 
have time, to throw themfelves flat on 
Account of the Coal Maines at Whitehaven. 
The cffeét of the bad air, in 
319 
the ground, and to bury their faces as 
far as they can in the mud. : : 
Of thofe who die, fome have fcarcely. 
any marks of burning 5 others are {corched 
all over ; others, again, have no external 
wound atall. The effects of this foul 
air are very fingular: they may be com- 
pared to thofe of gunpowder, fired in a 
clofe place. Thofe within reach of the 
flame, are quite roafted, or at leaft much 
burnt; the reft fuffer by the rapid and 
great dilatation of the air, which imme- 
diately takes place ; thele are infallibly 
fuffocated, if they do not fecure them- 
felves againft the great condenfation and 
compreflion of the air which fucceeds, 
by throwing themielves on their faces in 
the mud, ; 
We are afured, that when an explo- 
fion of foul air happens, there are fewer 
men killed by the fire, chan by what they 
call the return of toe air [or olaff] and 
which may be called condenfation. J 
have converfed with a maffcr miner, who 
has been burnt four or five times, and 
who bears very evident marks of it upon 
his face and hands: he informed me, that 
he always avoided the return of the bad 
air, by throwing himfelt fat onthe ground 
with his facein thé mud. Thetwomea 
who perithed two days before I was inthe 
mine, and with whom the above-men- 
tioned perion was, were killed by the re~ 
turn cf the air, and were not at all 
burned; whilft thefe who were with 
them were burned, but in no danger of 
lofing their lives. ; 
Another very Gngular circumftance of 
which I was informed, is, that perfony 
fuffocared by the air, preferved heat ia 
the joints of their bodies, and were not 
if till after two or three days. It is 
aitonifhine that, with fuch frequent ac- 
cidents, they do not employ all imagina~ 
ble means [ 4e a | to fave thefe poor un- 
fortunate people, who probably do not 
die till a long time after the fuffocation. 
The upperleamoi the mine at Work- 
ington is not at préefent wrought. It con- 
tains in its old workings, a vait quantity 
of foul air. From thele to the day they 
have conduéted a {mall tube, the mouth 
of which is not more than an.nch anda 
half in diameter; from this tube, there 
continually iffues a ‘itream’of bad dir, 
which is fet on fire and burns perp:tually, 
throwing up a sec of flame, about a foot 
high above the mouth of thetube. This 
flame, is eafily extinguithed, by giving it 
a blow with a hat: after which, if the 
finger be applied to the opening, a cool 
{treana 
