Evening star., 1922-06-21
MARCON |NVENTS
RADIO SEAR|C:H|L|GHT
Reflector, Centering Rays on
One Point, Seen as Ship.
.~ ping Aid.
By the Associated Press.

!
,, NEW YORK. June I'll Senator
Guslielrno Marconi wonder man of wire
less. last night announced the invention
OF what might be termed a radio search
light. by means of which radio waves,
which can be reflected like light waves,
may be sent in given direction in
beam. instead Of being scattered to all
points OF the compass
| the famous Italian said he believed
this invention could be utilized in such
| manner as to rid the sea of some of its
! tsrrors. for with a revolving reflector
the transmitter would constitute a radio
| iighthouse, capable of flashing guiding
beams nearly hundred miles.
| ADDRESSING Joint meeting of the In
! stitute OF Radio Engineers and the
American Institute Of Electrical En-
| g1neers on his latest discoveries. the in
ventor said Of the proposed radio light
house:
| BY means Of the revolving beam Of
electrical! radiation. it is possible for
to ascertain in thick weather. the bear
ing and position Of the lighthouse.
| Advantages of Device.
| 1T seems to me that it should be pos
slole to design apparatus by means Of
which a ship could radate or project
| divergent beam of the short wave rays
In any desired direction, which rays. il
| coming across metallic object. such as
| another steamer. would be reflected back
to receiver on the sending ship and
| thereby Immediately reveal the presence
| and bearing of the other ship in fog or
/, thick weather. One further greater ad
! vantage of such an arrangement would
| be that it would be able to give warning
Of the presence and bearing of ships,
\ even should these ships be unprovided
with any kind Of radio"
Marconi's radio searchlight bears
| little resemblance to the battleship
searchlight. 1t is, rather a special
arrangement of wires on towers or
masts. During his lecture Marconi
| exhibited pictures of refiectors. re-
sembling the weird apparatus pic
| tured in imaginary tales of the con-
quest of the world by Martians
| Through the use of these ref1ectors
| changed during experiments over a
distance of ninety-nine miles. be-
! tween London and Birmingham. he
announced, establishing record in
long distance radio transmission and
reception with short waves.
| Sends and Receives Together.
| Marconi stated that the reflectors
reproduce a radio telephone song or
| speech about 200 times louder than
is ordinarily possible. What is more.
| speech is transmitted practically
| without distortion. and the transmit
| ting aerial can be used both for send
| ing and receiving at the same time.
In these days of broadcasting it
may still prove to be very useful to
! nave a practically new system, which
! will be to a very large degree secret
when compared to the usual kind of
| radio" he added.
| hnl bof n
| the development of radio communi-
/ cation. the longer wave lengths have
so much absorbed the attention of
| inventors and engineers that the time
has come to conduct research in
! short wave length radio. OF around
! the world wireless. he said, he had
| obtained results (which go far to
show the relative facility with which
| radio signals can now be sent from
| England to Australia. and seem to
! Indicate that there is something in
| the idea Of the wireless waves trav-
| cling around the earth by various
ways and reuniting at the Antipodes.'
! Sometimes these radio waves, traV-
cling around the earth in different di-
lrections. reinforce each other when
they meet at the receiver, said Mar
conf, and sometimes they interfere
with each other He declared that
l the great station built by the radio
corporation of America at Port JET
! ferson, Long Island. the most power
full on this continent. sent waves that
..preferred to travel three-quarterS
Of the way around the earth. rather
than to come by the shortest way
round"
| Further Discoveries.
! Marconi discovered that when short
waves are used disturbances caused
! by static can be said to be almost
on-existing and the only interfer-
ence come from the ignition appa-
ratus of automobile and motor boats.
Incidentally" he added. II might
mention that one of the short wave
receivers will act as an accurate de-
vice for testing whether or not ones
iignition | system is working all right.
Some MOTORISTS would have shock If
they realized how often their igniters
and spark plugs are working in
deplorable irregular manner"
! To overcome static, Marconi first
determined the strength of the signal
sent by measuring apparatus and
then makes the signal strength equal
to that of the distance transmitting
station.
"If the signals are unreadable. due
to static" he explained, the measur-
ing apparatus is used to send to an
operator at a standard rate of twenty