The workingman's advocate. [volume] (Chicago [Ill.]) 1864-1877, 1875-02-20

fall down to the lower opening by its own
superior weight, just as the two-pound
weight referred to would, therefore the
cold air Ia the mine would not have bal
ance.
Nov, Mr. ID. Med. says his experience
teaches hun that IN summer time, when
the air Of any mine is cooler than the at
mosphere above ground, that there Is no
curren; Of air at al, natural OF otherwise,
and that In such a case no ventilation, nat
ural Or artificial, can take plsce, except II
BE compelled By som, mechanical power;
which, say, is great mistake, for there
IS about nine out of ever ten of the mines
around Pittsburg that have no mechanical
power at all, ana depend entirely upon
natural currents caused, as before seated.
by the difference q temperature. But it
is poor way putting trust III Providence,
as | have been told To do often
lie ssain says that Mr.. Roy states that
a mine would be- better ventilated all the
year around II the furnace Was at the low
est opening IL Mr. Roy did say that, he
vas mistaken; ior if We must come down
" tine points Ia regard to hillside mines
ventilation, II would heeef two furnaces :
one 90 ASSIST the natural downward cur
rent .D summer time, and TIE other 70 a.
sssis. ;Le natural upward current in
winter
But this Is not needed. If there Is a
furnace at the higher opening il will be
sufficient. for 1t vii make the air IN the
upcast much better than the ar outside,
even III summer time. and consequently
produces circulation.
Again. Mr.. Roy says that shallOe suines
are more difficult to ventilAte than deep
ones. ard he is righl when he comes Ia
shaft ventilation, for ia a shaft 100 feet
deep there would only be ane-half the
weight OF air IN the downcast shaft as
there would b+ in a doNucast shaft 200
feet deep, therefore only one half the ven
tiiation power IN the shallow mines as in
the deep mines; and a. Tor the expense
that Mr.. d. Med. talks 50 much about. it
would be Just the same, providing the
mines were equally extensive under
ground, for with the same mode II ventil-
alton there would he the sane number of
doors and stopp.ass used.
Mr.. Roy also states that unless mine
managers and coliiery pIrprietors learn,
and act on, these facts. they will never
| have good air III mines and that is Just
as certain a. | live. And then Mr.. ID.
I Med. says, as It happens, he has been a
mine manager for great many years, and
he does not think he can learn anything
! from MIR. Roys assertions that would i'll
any way better the mode ID ventilation.
That this Is his practical experience sounds
strange 10 me, for h. says there is u, nst
ural currents II all IN a mine IA the sum
rner Tune If that IS true the mines could
not work only in the winter. This state
iuent IS not true Ny experience teaches
me that the hotter the day the more rapid
the air travels from the higher opening TO
the lower one, Of those hillside mines
around Pittsburg. and the same cause pro
duces the same effect, in all ages and places
of the world as hundreds Of miners here
can testify. You can see how much he has
learned by his experience; and II he wants
to learn little more he can come To Pitts
burg, st:7t. enquire Tor the Castle Shannon
Coal works, and | will show HIM Mr.. Roy's
theory IL practice any day, he comes,
with great pleasure. As he SAYS it would be
worth while seeing air travelling down the
higher opening IN summer time.
In conclusion, | vii say few words by
way 81 advice to Nj Med. If lie viii
get VIM Hepton's book ON Ventilation,
entitled Conversation between Father
and Son, or any Other treatise on natural
sciences, including he science Of pneu-
matios, he will do well for there he will
learn Mr.. Roy's theory. and probably be
more startled than ever At least have
no doubt but he wit ] forgot to say, as
it happens | hav. 0e-n working IN and
about coal mines for tAenty three years.
Hoping you Wi find space in your valua
bic paper,
remain. yours truly,
! " n