Richmond daily register. (Richmond, Madison County, Ky.) 1917-1978, 1920-06-07
USE CEOPHONE
In MINE WORK
Listening Device Invented During
the War Found Valuable
in Industries.
LOCATES ENT0MBED Miners
Greatest Value in Mining Will Be In
Connection With Rescue Work.
Can Detect Human Voice
$50 Feet Away.

NdSillHS COn.-AIter series OF I'M
portant tests with the geophone, a
listening device invented during the
war by the French, to detect and To-
cate enemy underground operations,
the bureau of mines, department of
the Interior announces that this deli
cate instrument may be put to a num-
Der of remarkable uses in mining and
other industries.
The most extraordinary result of
these tests is that the bureau of
mines men have been able, not only
to hear and locate sounds through the,
earth, but have actually understood
talking through 90 feet of solid coal
and have detected the human voice
fully 80 feet away. What this may
mean in the near future can only be
conjectured. An engineer of the br-
reau was able through 500 feet of
coal to distinguish nine out of ten diff
ferent coal mining tools that were
used at different times, so character
istic are the sounds. In one mine
where experiments We're being made
at the face of tunnel, the mine fore
man who was listening heard work
men in another tunnel preparing to
blast and ordered the engineers TO re
tire until the blast was fired. Tho
sounds were so clear he did not real
ize that the tunnel headings We're over
800 feet apart
Value in Mining.
The greatest value Of the geophQne
in mining, so far as known, will be in
connection with rescue work in mines.
Quite frequently miners are entoInhed
in coal mines following explosions.
and these men may be located quickly
and accurately through the geOphone.
In metal mines also where men may
be imprisoned behind falls or be bar
ricaded in some part Of the mine to
which they have retreated in order TO
protect themselves from the fumes of
fire-these too may be rescued
through prompt location.
When the bureau first began it's ex-
periments with the gsophone, it was
questionable whether the geophone
could hear sounds far enough away TO
make it practicable. The experiments
show that sounds can be detected
through the earth a distance of 1900
feet in a mined-out area in c0af
mine, through solid coal, 1000 feet
The geophone is also of great prac-
teal value in metal mines where two
tunnels have to be connected. Ar
times in spite of as correct surveying
as is possible the two tunnel headings
fail to come together. Just recently
bureau of mines engineers were in @
mine where the two ends of the tun-
mel failed to meet, and the geophones,
locating the error, showed the miners
the right direction.
Locates Fire in Mine.
Observations with the geophone
have also been made at mines which
were on fire, where it was found that
the fire made noise enough to be
heard some distance. either because of
its drawing air or the breaking off of
bits of coal and slate. The geophones
by thus locating the fire give infor-
nation which may enable the mine
management to erect fire stopping in
the proper places or to make direct
attack on the fire as for example by
drilling holes for injecting water to
the seat of the fire.
It is also the custom in some min
ing localities to drill hole from the
surface into mine to carry pipe lines
or cables. Oftentimes these drill holes
do not go to the right places, and it
is with considerable difficulty and ex-
pense that tunnels are driven to
meet the drill hole. With the aid of
the seophone the drills can be guided
better, especially since drilling can be
detected for nearly a mile.
Very satisfactory results have been
obtained In attempts made to- locate
leaks in water mains. The water cir
culating in the ordinary city main can
be heard with the geophones when
! they are placed on the surface, ten to
twelve feet above the pipe. In the
business district of Pittsburgh one
leak was located within few min
utes, although the water department
had been trying to find it for two
! weeks. r