Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-10-25
RADIO AGAIN FINDS
MINERAL DEPOSITS
New Use in Mine Safety and
Prospecting Promise I'm
portant Results.
BY MARTIN CODEL.

! (N.A.NA). Radios utility in detect
I ing mineral deposits has already been
proved. Mining men are now seeking
to adapt radio communications to the
problem of safeguarding miners. Results
already achieved in receiving radio sig
nails in the bowels of the earth hold
promise for this new use of radio.
To carry on experiments looking to
the adaptation of radio to mine safety,
Prof George r. Swenson of the Michi-
gan College of Mines has applied to the
Federal Radio Commission for authority
! to use a group of wave lengths. Not
only does Prof Swenson propose to set
up radio communication facilities for
emergencies like explosions or cave-ins
which entrap miners, but he wants to
study the vagaries of radio waves in the
copper country of Michigan.
Mineral Deposits Handicap.
The absorption of radio energy by
mineral deposits has often proved a
handicap to radio reception in the re-
gions near them. Not infrequently peo-
pie residing on the iron ranges of Min
nesota and in the iron and copper Sec
lions of Michigan find radio reception
almost impossible, except from nearby
stations.
That radio waves penetrate into the
earth has been proven conclusively, but
the extent of such penetration in diff
ferent kinds of strata and under vary
ing conditions is still subject of scien-
tific speculation. Research alone can
answer many questions in the minds of
scientists about the absorption effects
of earth deposits. Several other engi-
neerS beside Prof. Swenson have applied
themselves to the problem.
DR.. A. S. Eve. president of the Royal
Society of Canada, has worked several
years on a study of the possibility of
transmitting radio signals from points
far underground and receiving them be-
low the surface of the earth. Most of
his work has been done for the Canada
Geological Survey cooperating with
the United States Bureau Of Mines.
Penetrate Rock Deposits.
Several months ago DR.. Eve and Dr.
D. A. Keys, both of whom are on the
faculty of McGill University, found that
radio waves would penetrate the rock
deposits over Mammoth Cave, in Ken
lucky, to a depth of about 800 feet.
They found that the short waves could
not be tuned-in, but the intermediate
broadcasting frequencies brought in pro-
grams from various stations. Their
aerial was strung along the roof of the
cave.
Similar experiments have been car
ried out successfully in coal mines in
Pennsylvania and Colorado and in the
Mount Royal tunnel. near Montreal, by
DR.. Eve and his co-workers.
A report recently told of good radio
reception In a salt mine at Hutchinson
Kans., nearly $50 feet from the surface
Using an ordinary receiving set, with
antenna strung along the mines tim
bers, the experimenters tuned-in pro-
grams from stations as far away as
Chicago, Louisville and Cincinnati.
Good in Caverns.
M. 3. King of New Market, Va, is
authority for a report that radio recep-
| ton is good in the Endless Caverns, one
of Vireinia's unique caves. Tourists
visiting the caverns have been enter
! tanned with radio programs, he stated.
Several broadcast presentations have
! been staged under water. but these