Ottumwa semi-weekly courier. [volume] (Ottumwa, Iowa) 1899-1903, 1902-02-13

tached for violation of any rule laid
down for the protection of the shot
ffrers.
If the above suggestions were put
into practical effect, the consumer
will ask, What will our coal cost u.s."
To this | answer, mot to exceed 2He
cents per ton on a fair estimate. III
this statement is questioned | snail De
glad to furnish data to prove and sub
stantiate my claim.
Again, how often have We known an
inexperienced employee to jeopardlze
the lives of hundreds of men? Hence,
in view Of such astounding and incon-
trovertible facts what are we entitled
to as miners? Answer, "Shot firers."
And if we fail to have the same incor-
porated into law, then | ask, What
must be done in justice to the occa-
sion?" We should have liability act
passed, and when it was clearly estab-
lished that one individual employe
through negligence or otherwise caus-
ed the so-called dust explosions, the
coal companies should be liable for
damages, etc.
l understand that at Lost Creek.
where the recent sad calamity occurred
the miners use only squibs. Will MI.
Phillips please make a note OF this?
In conclusion, permit me to congrat-
ulate the Courier for the position it
takes on this question as enumerated
in an editorial few days ago. when
it declared that if the company was
responsible for the hiring of shot firers
that none but the best and most COM
Detent men would be hired for such
work.
James Nevin, Engineer, keb.
The blame is not on the miner as
is generally expressed for careless shot
firing. Competent miners should con-
stitute the majority of the commission
to be appointed to investigate the
cause of explosion in Iowa mines.
| will say no miner is sure of what
his shots will do at all times, The
coal is not of homogeneous nature,
There are unforeseen rocks, slips, faces,
partings and uneven roof and floor
that prevent shots from doing what
was expected of them. If powder
enough is placed in a mine and ex-
plooCu IL Will WlSSh li.y NASAA
is the case with explosions. Heavy
shot firing has broken doors by the rap
id expansion of powder into gas and
has also loosened the coal required.
There is quite large quantity of pow
der exploded in firing large number
of shots and in rapid succession in
close workings causes the ignition OF
the carbonic oxide gas and the sus-
pended coal dust given off by the first
shots which have not had time to
diffuse or become diluted by the air
current before it is ignited by the
fame of the following shots. Now the
temperature and also the mine pres
sure by the heat and expansive force
of each shot is greatly increased. Does
not this added pressure exert a repel-
ling force against shot that was ex-
ploding at the time this pressure is
the greatest and tend to force the, eX-
ploding charge to the place of least re-
sistence (the tamping or a seam in
the coaD blowout shot that will
ignite the carbonic oxide &c. o. and
coal dust of the first shots fired ?
(Carbonic oxide gas has the widest
explosive range of any gas except by,
drogen When one volume of the gas
is mixed with about 81 it's volume OF
| air the lowest explosive mixture is OBJ
tanned From this point it continues
to be explosive until the proportion Of
gas is increased to the extent of one
volume of gas to every 1.6 volumes OIL
air 1t is this property OF carbonlc
oxide gas which makes it such an &C
tive agent in transmission of the flame
of mine explosion from one point in
the mine workings to another.)
Now we have one whole locality ex
banding, raising dust which feeds this
force by the distillation of the coal gas
in the dust which is carbonic oxide
&c. o.. The temperature of BLACK
powder exploding is practically 1900
degrees F. of carbonic oxide, 1,1S4 de
grees F.
Some remedies: Sis
The best grade of powder should be
used always. Cheaper grades of pow
der are often made by substituting
sodium nitrate for the potassium nj
trate. either in part or wholly, bu
such substitution produces very in
ferior powder.
The air current should be divided as
often as possible. Should an explo
zion occur In any part OF the mine 1t Is
more apt to be confined to one localit.
| if the dust is kept wet between eacf
locality.
| There should be lesser number Of
men allowed to work upon one air cur
rent. 1t is not the amount of air that
goes down mine, it is how it is dis
tributed that makes efficient ventila
ton. 5a
There should be limited amount
of powder exploded in EACH working
place by one man only in that place.
! There should be system of firing
shots in rotation, beginning on the re
turn air current, in order that thu
gases from the shots fired would moi
pass the shots firing.
4 Or, if the system of mining could b.
changed from blasting off the solid tc
mining by pick, a more eXhaustiv'
mining and better marketable condi
ton of coal would be secured, viz
length of life for the mine, less slacl
and 10 to 20 per cent more lump coal
Therefore a better selling price coult
be obtained. Now the weight of tn,
OVERLAPPING strata if properly managed
with very little or no powder will suf
| flee to loosen tho coal when mined