The workingman's advocate. [volume] (Chicago [Ill.]) 1864-1877, 1869-08-21
THE MINER.
ApseII's FIre-Damp InGIcatOr.


In 1874, the coal and Iron-stOne mines Of
Great Britain numbered 1920, and the COM
ruted number of male persons employed was
307,542. It appears that Of these one life
in 854 was lost by accident during the year,
and that for every l09,7l8 tons Of coal re-
covered and brought to the surface one bu-
man life WINS sacrificed Beside the fatal
accidents, there is fearful array of contu-
rions, fractures, maimings, amputatione, &C.,
SO that the record Of mining accidents reads
more like the description Of q battle field
than the ordinary report Of industrious and
peaceful pursuits.
This heavy mortality shows that the means
at present employed to indicate the presence
of FIRE damp are inadequate. Much evil,
however. results from the recklessDess and
Ignorance Of the workmen. The "Davy
lamp" is constantly being tempered With
the "Geordie'' ia not held in much favor
and the Dumas lamp docs not yield cuff
fcient light to enable The miner to see his
work. The Davy lamp serves, however, to
indicate the presence of fre-damp. Mr.. G.
F. Ansell, OF the Royal Mint, now offers to
miners and mine. owners a simple and beau
tiful fre-damp indicator, by means of which
the presence of the smallest per- centage of
fre-damp OF choke damp is immediately
detected. We give description in his own
words:
"Ibe apparatus is of three kinds. The
first consists Of diffusiometer, an electric
alarum, and a small galvsnic battery, the
whole being arranged under a small stand,
Of sufficient portability for the miner to car
~ with him into the heading where be 10 at
work, and upon a sudden irrurtion Of fire.
damp the alsrum is rung instsntsn eously.
It's action may be explained in the following
manner nt Tie e5Tlr2lcmeteT .Gc1,is.l.ls q
bent Tube ID the form of q letter U, having
at one end a cup or chamber, the surface of
which is enclosed by a piece of porous tile. !
This tube is partially filed With murcury.
" hen the FIRE. damp surrounds it, diffusion
Of the gas takes Ilsce through the porous
tile, COMPRISING the volume Of air within
the cup, and thereby forcing the murcury
doWnwsIds, which rises in a corresponding
manner in the opposite side Of the tube
this 10 made to form contact with one of the
terminal poles Of the battery, and the alarm
Is given. By proper adjustment il can be
set 10 indicate will in five seconds after the
irruptiOn Of gas The second form Of in
strument is for Indicating gradual accumu-
lation it consists of an inflated india rub !
DER DAll, MDlcQ Is QGeQ III u lEames OiuO- =
zion takes place through the surface Of theg
ball, causing it to expand. Tbs force is sp- !
piled BY mechanical arrangement to COM I.
plete the circuit Of g battery, and by means
of a telegTaphic wire it will indicate at the !
mouth Of the Fit where the air of that par I
ticular part Of the mine is explosive. These I
instruments could be placed in different
parts Of the mine, and by simple system.l
Of telegraphy a perfect knowledge of the;l
state Of the air would be bad by those above
ground and in the Gaze Of a gradual accu-L
mutation taking place in the night during
the absence of the EineTs, the affected park
Of the mine would be indicated at the mouth
of the pit. The third arrangement is for
indicating the presence Of fire damp ant
measuring its quantity. 1t is an adaptation
Of the aneriod barometer, and is extremely
portable, being little larger than an ordInat
~ watch. The instrument Is graduated II
The ordinary barometrical scale, and can b
used as barometer. When not required as
a fTe-dsmp indicator a small valve is at
taehed, which, beng open, admits the at
mOsphere, and the instrument acts ss bare
ometer but, when closed, the admission G.
gas must be through a porous tile, WHICH
causes compression as before explained
ard the indication is given by the hand UE
on the dial. The indications are unvarYiD9,
100 per cent. Of fre-damp being indicated
by l. $50 inches Of tho barometrical seals,
and 10 per cent. BY O-l30 inches II will also
determine the amount Of carbonic acid y
ct oke-dsmp, the hand moving in the opp
cite direction to that for fre-damp."
In order to render the description fulEy
ineligible, We append description Of Tie
constr uction Of the aneIoid barometer.