3A4 
consists in carrying eurrents of at- 
muspheric air thtough every possible 
eutting, and of directing the profuse 
issue of gas into the line of draft, by 
what are called stoppings; that is, by 
turning the gaseous course by doors, 
or brick-work, so as to facilitate its 
passage by the most easy, and least 
darigerous, channel, towards its aper- 
ture of issuic, the upeast shaft. ‘The 
course of an atmospheric current 
through the windings of a working, 
about 600 yards square, is estimated 
at twenty-seven miles. 
The Sunderland Society for prevent- 
ing accidents in coal-mines, in their 
first Report, say, “*The only method 
we are at present acquainted with, for 
preventing accidents by fire, is a me- 
chanical application of the atmospheric 
air to the removing, or sweeping away, 
the inflammable gas, as it issues from 
the seyeral fissures which the workings 
intersect in their progress.” — 
. One method is, that of forcing air 
down the shaft, and along the courses; 
but this is deficient in power for the re- 
moval of so large a volume as they 
contain. 
A second is, by falls of water, carry- 
ing with them a current ofair. This is 
nut only subject to the objectionagaiust 
the former, but also to that of the ex- 
pense and labour in again raising the 
Water out of the mine. 
A third is, the use of the air-pump ; 
which is not only unequal to the de- 
sired effect, but also, while acting, ren- 
ders the upcastshaftuseless to the miner. 
A fourth is, that of a furnace, near 
the bottom of the upcast shaft; in order 
to rarefy the current passing up to it, 
and draw, along with it, the air of the 
courses, This method is highly dan- 
gerons; for, if an extraordinary issue 
of gas should rush from a line of work- 
ing, and come in contact with the fire, 
destruction would be certain. 
A. fifth is, the diluting method; 
whereby so much air is carried, or 
forced, through the workings, as shall 
dilute the generated gases below the 
point of combustion. ‘This means will 
succeed, where the coal-seam is thin, 
and the gases not abundant: and his 
been eflectually adopted in some of the 
Staffordshire collieries. ? 
The last method to be mentioned is, 
that of the firing line, as it is termed. 
This is done by men accustomed to the 
process, who, having prepared a light 
under the gaseous accumulation, or as 
near to it as possible, retire into a 
Proceedings uf Public Societies. 
[Név. I; 
stable, well scoured; and, by pulling a 
properly-directed wire, bring the light 
into contact with the gas, when an 
immediate combustion and explosion 
take place. Insome mines, where the 
accumulations are profuse, it is neces- 
sary to fire them three times daily ; and, 
as the miners are all obliged to retire 
during each firing, there is a great loss 
of time. Besides, there must be im- 
mensc pillars of coal left uncut, or the 
firing process would tear them down, 
and involve the whole works in de- 
struction. Sometimes, too, the ignited 
gases set fire to the coal-seam itself, 
and it becomes necessary to stop up 
the shafts, until the extinction be ae- 
complished. : 
Mr. Ryan considers thatthe carrying 
a traverse all round the working is 
essential to security, so that the head- 
ways may all terminate in this sur- 
rounding channel, and therein pour the 
collections of the respective cuttings 
and head-ways; these are, in course ef 
current, from the inferior to the supe- 
rior level of the mine, and terminating 
in an enclosure, trom which is carried 
a gas-way, running npwards, like a 
chimney, into the upcast shaft, a few 
yards above its bottom, so as to secure 
the gaseous current froin contact with 
the lights necessary in use near to the 
floor of the shaft. 
When tlie horizontal line of the seam 
is broken by perpendicular fissures, 
filled with foreign matier, and the an- 
gular inclinations of the bed are re- 
versed; he would carry a boring from 
the upper part of the lower leg of the ’ 
angle to a point of the superior leg, on 
a higher leyel than that from whence 
the boring commenced; and render 
the whole as effectually drained of gas, 
as if the stratum were one unbroken 
and oblong plane of working. By 
carrying collateral cuttings from gase- 
ous accumulutions, whether produced 
by basins in the roof, or fallings-in of 
earth, into the serrounding head-way, 
or gas-channel, he provides against 
local evils. And, in some instances, 
where the gas issued from vents, not 
easily connected with the head-way, 
he closed the cavity in, Icaving only a 
small aperture for its egress, to which 
he set fire as a jet, and thereby con- 
verted intoa useful light, for the miners 
without to work by, what, if lighted 
when freely expansible, would have 
exploded, to their destruction. Per- 
haps this is as beautiful an instance of 
skilful application in science as “+ 
ec 
