The Washington times. [volume] (Washington [D.C.]) 1902-1939, 1928-08-20
RADIO ECHOES
CAUGHT BY
CAMERA

nY 1nternatIonal SCI Lie

CHICAGO. Aus. 20 Radio
echoes, the kind that interrupt the
reception Of musical hroadcasts with
occasional dots and dashes Of code
messages. are being traiIed by
scientists at the University Of Chi.
cago.
Just where the paths OF these va
grant radio flashes will lead Is .
subject OF considerable speculation.
According to the theories under
consideration BY the investigators.
the ''echoes' may bounce on the
layer OF electrons lying anywhere
from as to 400 miles above tha
earth and then return to the earth
before they are picked up.
Again, they may travel up to the
North Pole and thence back to the
radio receivers in civilization. or,
they may 60 only as Tar as the
North magnetic pole and return.
still another theory being considered
II that they strike the mountains
and are DETECTED BY them.
PhotOgraphing Echoes
In an attempt to prove or dis.
prove one OF these possibilities. Or.
j. Barton Hoag, instructor in radio
activity in the University Of Chi
cago, ana Victor Andrew. one Of
the graduate students In the depart
ment. spend sleepless nights in
Ryerson Physical Laboratory At the
university catching photographs Of
| the echoes"
Their efforts. they believe. will
prove fruitful in solving the ccndi-
tions of the upper atmosphere
which affect long range radio work
and explain what happens when the
suns rays strike the earth's at
mosphere, forming roof Of cleo.
irons over the surface Of the earth.
1T has been known previously that
radio signals on short wave lengths.
under favorable conditions. travel
around the world as many an TIRES
timesg being received at intervals Of
one-seyenth Of a second. This
much scientists could understand
easily. But what about the other
echoes" that followed the direct
radio signals at intervals Of from
one one-hundredth OF q second TO
four one-hundredths Of q second.
These echoes could not travel
around the world in that time az
radio waves travel at about the
same speed as light or approx.
mately $4,000 miles per second.
May Bounce Back
1T Is known that there IL d
radio-resistaYat layer about the earth
known as the Kennedy Heaviside
layer. made up of strata Of cleo
irons created by the SUM- DR..
Hoag said. THE distance OF this
layer Of atmosphere varies with
the time Of the day and the season
of the year.
''It il possible that some OF these
vagrant signals which people often
hear in radio reception, are signals
which have left the earth, struck
this layer. and then have been de-
Elected back to the earth.
This theory will explain some
OF the echoes that we have been
recording. But we have found
many that must travel greater dis
tances than to the layer of cleo
far as the distance around the
world.
1T may be that these vagrant
waves circle the North Pole ana re.
turn. 1t il possible that the Ken.
nelly.Heaviside layer forms a deep
bowl there, rising 800 miles above
the normal layer, because OF the
influence OF the six-month day.
Then it is possible that some Of
these radio waves only so as far
as the North magnetic pole and
then return. have been in con-
| ference with members OF fhe geo.
detic survey and / am comparing
their chart Of magnetic disturb
ances with our records"
If the cause OF the echoes" can
be discovered. it is possible they
may be eliminated by proper direc-
ton at the source of the signals.
Dr. Hoag also suggested that this
| step might lead to the control Of
radio beams so as to make them ac-
cessable for the transmission OF
power without the use of power
| lines.