The workingman's advocate. [volume] (Chicago [Ill.]) 1864-1877, 1875-06-19
CORRESPONDENTS.
We do not hold ourselves responsible for any opinion
EXPRESSED by our CorreSDondents
f6OM ILLINOIS.
MINoNK, May 20, 1875.

MINoNk, May 20, 1870.
To the Editor Of the WokEKaNAS's ADVOCATE
In your issue Of the oath Of April,
notice a letter from W. H., of Fair Haven,
Pa, wherein he tries to prove from my
letters an assertion he made in the ADvo-
CATE, to-wit that don't understand the
nature Of air He finds his first proof in q
letter of mine, dated March II. take
liberty to quote from said letter, for the
reason that | can give it better justice than
he has done. 1t reads, viz In the mines,
together with the atmospheric pressure from
outside. This he says is wrong, for the
atmospheric ipressure has nothing to do
with causing the natural currents Of air in
mines. Rut To test whether the atmos-
pheric pressure has anything to do with as
sisting the natural ventilation, let them be
selected lin the winter season when natural
ventilation is in full force). A mine having
two shafts, one the upcSst the other down
cast, on the north of the downcast place an
air tight covering. Immediately after the
ventilating current Of air will cease to eX.
list. Why, because atmospheric weight or
pressure has been cut off then to take OF the
covering alluded to, and give again free
access to the atmospheric pressure from
outside, and Immediately after doing so
the natural ventilating current Of air will
resume its former velocity With the
above test, MIR. w. H. must admit Of a
propeling force, and if not from the at
mospheric pressure, pray where does it
come from. His next proof is quoted from
the same letter, viz What is the cause
Of the stagnation of air currents in mines
through the summer season. Because the
air in the mines is then generally colder,
consequently denser than the atmosphere
above ground. ". II. says, here | am
wrong again, and goes on to state, that the
real cause of the stagnation of air currents
in the summer season is this, namely !:
That the air becomes Of the same tempera-
ture, both i'll and outside Of the mine.
think a test can be made to show that il
is quite possible that Mr. W. H. might be
wrong, viz Let some person take a
thermometer any day through the summer
when a stagnation Of the air currents has
taken place, take the degrees of temporal
ture outside, then go down the shaft, tax
ing the degrees of temperature as they 20
down to the bottom. The above test will
show who is wrong to certainty. His third
proof, that | don't understand the nature
of air, consists in what he would try to
make contradiction that he found in my
letters. W. II. writes thus, to-wit Now
he says there are natural currents Of air in
summer in a mine and reverses dozen
times day, more or less. This is differ
ent from what he stated in his former let
tiers, where he states there are no natural
currents Of air in any mine in summer
time. W. H. then makes a mistake. In
my first letter wrote no natural current,
and not currents as he would try to make
it appear. Would w. H. take dollar in
place Of dollars at pay day. ] think not.
still say that there is no natural current
Of air through the summer time, and yet
say there are natural reversing currents
through the summer season and fail to see
any contradiction in saying so. Can W.
H. say there is a natural current Of air in
any mine throughout the summer time
certainly not. Reversing currents there are
he cannot deny. ! have the presumtion
to believe that the proofs he has advanced
fall short of the mark intended.
Mr.. Editor, In your issue Of May 3,
notice a letter from a Marylander. He
says he thinks Mr.. Ray is right in saying
that mine would be better ventilated all
the year round, if the ventilating furnace
is placed at the lowest opening, for the
simple reason, that at Hoffman's Hollow
Slope, in Allegheny Co., Md, he says
they have eight months in the year that
the natural current will be TO the lowest
opening. ! would say to q Marylander
(although it may surprise him and spoil
his reasoning) that at Minonk Shaft,
woodford Co., ILL.,, we have had eight
months in the year that the natural cur
rant has haon II the higher ODeninO