The West Virginian. [volume] (Fairmont, W. Va.) 1914-1974, 1922-11-29
'WOULDUSE RADIO
NNl||N|I.E !. DISASTER
Preliminary Tests Are Being
Made by United States
Bureau of5Mines. {.

WASHINGTON, Nov. 2s.A
Radio communication between re-
scuers on the surface and miners
entombed in mines following fires
and explosions Is q hope held out,
by the United States Bureau OF
Mines to lessen the horrors and
losses OF mine disasters. Prellms
mary tests conducted by tao
bureau, with the cooperation Of q
great electrical manufacturing
concern, IN an experimental mine
at Bruceton, Pa, already have re-
suited In q degree Of success.
While these experiments hayn
so far failed to develop any prac:
tical method OF using wireless
waves for underground communi-
cation, nevertheless, says a publ.
cation Of the mines bureau, they
Indicate clearly that eleSnomag.
netic waves may be made to travel
through solid strata. IN the Bruce
ton experiments signals were
heard distinctly through fifty feet
OF coal strata, although the audi
bility fell off rapidly as the dis
lance was increased. The absore.
ton Of loss OF intensity with dis.
tuace Is very great for the short
wayee lengths used In these tests
Longer wave lengths are known TO
suffer less absorption and may
possibly be found practically etfee-
tive under certain conditiogs.
In this connection It Is interest
ing to note tests conducted by Vls
United States Bureau OF Standards
In dropping wireless antennac,
down deep, unused oil wells to uu-
derlying rock strata, IN order to
send the wireless impulses through
the rock instead OF through the
air. The results, It is believed.
may be the same as pro jecting the
antennae upward into the air
strata.
The desirability OF substituting
the wireless system OF communica-
ton for the present telephone sgd.
TEN in use In mines Is evident IN
considering that a rock fall or ex.
plosion, by breaking wire connec.
tions can put the entire system ont
Of order.
The mine telephone has been
perfected to, such an extent that It
Is giving satisfaction In most
mines where the wiring Is we'll 10.
sulated, the Bureau Of Mines an
nouncement continues. Very often
the telephone cannot be depended
upon on account OF falls OF rock.
grounding due TO worn insulation or
extreme dampness q In the event
.of disaster It frequently happens
that the mine telephone system Is.
put out Of commission by tho
agency that causes the disaster.
at thefyery time when it Is most
needed. On this account
the mining industry Is Interested
In any kind Of telephone. system
thaEEcan bee counted upon In N
emergency. Many requests have
been received by the Bureau Of
Mines to devise means OF utilizing
wireless methods for this purpose.
The preliminary experiments
consisted first in receiving signals.
from without the mine by means
of receiver located inside the
mine and second, both sending and
receiving messages underground
through the strata. Il WINS found
that with. a receiving instrument
set alta point 100 feet underground,
signals sent from station KDKA, OF
the Westinghouse Electric and
Manufacturing Co.. at East Pitts
burgh eighteen miles away, could
be heard distinctly. fifty feet from
the receiving station used in the
mines in this test was a six inch
bore:hole extending from the sur
face, lined with iron pipe and CON
tanning electric light wires which
extended therefrom through the
mine. The presence Of these wires.
according to the experimenters.
evidently assisted greatly In the
reception Of the signals, for when
the receiving set was carried 20 .
another point in the mine removed,
from wires and tracks the signals
were barely audible through fifty
feet Of cover. The fact that sig
mails were detected at all, however
even though family, was declared
sufficient evidence OF transit ission
through ground to encourage fur
ther experimenting. .s,f
In sending waves underground a
transmitter was used in such o.
manner as to produce waves OF
greater length. 4 +.
+ In all experiments the vertical
antennae were found to Eve bet.
ter results The horizontal antan-
nae gave practically no reception.
"a loop Of a single turn was used 1
with fair results. All thees exper.
tments were tried with a wave
length Of 200 to 300 metres except
the reception from KDKA, which
was $50 metres.
The strata at the experimental,
mine lie almost horizontal. The d.
rection Of strata, It was Said,, may,
have some influence on the trans.
mission Of radio waves, but the
present experiments gave NO con.
elusive evidence on this point No
doubt the degree Of wetness OF the