Pioche daily record. [volume] (Pioche, Nev.) 1872-1876, 1875-08-22
WRONG ASSERTIONS.

In the Sutro Independent OF the l4th "a
inst. there is an editorial, comprising OF
nearly two columns, on the subject Of al
deep mining. It discusses the question N
of the heated air In deep mines and the a
best means Of obvisting this serious bar q
to success, and puts forward some very o
GOOD ideas relative to measures calcu-
lated to cool the air and put 1t at tenn
pera,ure endurable to the workmen. In =
speaking OF compressed mir as powerful !
adjunct in this cooling proct IS the writer
says:
II six cubic feet of mir having tenn.
perature of GO degrees, are compressed I
into ono cubic foot. the temperature OF
that ono foot Of compressed air Will De
800 degrees; if6rder to absorb this ex'
ira temperature the compressors are sur
rounded by cold, flowing water, whicn
soon reduces the heat of the compressed
air to 60 degrees ordinary temper
ature of the surrounding atmosphere.
We arc inclined to differ materially
from this assertion, and without presum'
wherein the mistake lies. Air partakes
strangely of tho properties OF its two
principal constituents, oxygen and nitro
gen, and though On extremely elastic |
fluid, can be condensed or compressed to
o degree but little inferior to that OF
water Zone six hundred and seventy
fifth part of it's original volume), without
undergoing any apparent change in its
physical condition. Heat expands it
and acts principally on the more active
principle or element OF oxygen, which Is
one of its component parts. Pressure
and temperature affect all gases in the
same proportionate degree; one thou
sand cubic feet OF air at 81 degrees De-
come dilated to one thousand three hun
dreu and seventy five feet at 2l2'. The
laws OF expansion and compression are
uniform and capable Of demonstration.
Now as to the first assertion; 1t IL pal
pable absurdity to say that six cubic
feet of air at q temperature OF 90 degrees
compressed into space OF one CUBIC
foot will evolve $50 degrees Of heat
There 10 no chemical or natural law thai
can be proddced to substantiate this er'
roneous assertion. There 10 n certain
amount of heat contained in all bodies
gaseous, liquid and solid, the
amount varying with the compo
nent parts of the substance. i
six cubic feet of air are compressed int
space occupying but one cubic loot
tho normal temperature of that air
increased only by the latent heat set IRE
BY such compression. The greater tn
degree of compression, the greater tn
amount of latent heat evolved whiol
would combine with the sensible heat
indicated by its mean temperature AM
increase the amount of heat In the al
very appreciably, but far below the big
degree so unwarrantably asserted. II II
assertion advanced by the Independel
was correct and capable Of affirmati'
substantiation, it would be one of Il
greatest things in science. The Keel
motor and Schroeder's air-ship would
left iu the shade, for the beneficial I
fects OF such evolution OF heat would
great and powerful. We will illus,ra
by supposing that such assertion is CT
rect; at once the necessity for II
ceases; by COMPRISING air into one-sis
OF its space degree Of heat would
evolved that would make steam
better and cheaper than fuel Ca
Water bois at 2l2 degrees, but II SIM
compression would evolve heat Of
degrees. the application OF such h
would do away with all need of fuel a
complete revolution iu the applian
of our present motive power wo'
ensue. The deduction from this ass
ton, as stated in our extract, will h'
to be modified in the same degree az
original premises. The argument is
made all along. but when writer sta
out With false premises. his line of =
sonine, however plausible, must nee
sarily be incorrect and full of flaws.
subject OF the ventilation Of mines is
eeedingiy important and a topic Of '
interest to oil connected with mining
dustres. Any theory in accordance W
natures laws is worthy of investiRat
and practical trial; but incorrect ssl
lions. however we'll supported, only 4
lead and mystify Gil inquiry of mind
desire OF practical Advancement
improved appliances.