The New York herald., 1922-06-21
Continued from First Page.

of feet in length. especially as remem-
bered that during my early experiments
as far back as 1895 and. 1896. / had OBJ
tanned some promising results with
waves not more than q few inches
long,
He then proceeded to describe how he
had returned to his original idea Of
using short waves and told his audi
ence of some recent striking sxperi-
ments that he had conducted with
waves OF one meter to twenty meters in
length
Mr.. Marconi said that because radio
waves can be reflected like light waves
he has devied method of sending them
In a given direction In beam instead OF
scattering them to all points of the COM
pass. What he described was a radio
seerchlight. The pictures that he threw
on the screen showed a reflector which
reminded one OF the structures that H.
G. Wells once attributed to the earth
conquering Martians. Marconi's radio
searchlights bear little resemblance to a
searchlight of battleship. They are
wires arranged in special way on
towers or masts.
In Italy he succeeded in thus reflect
ing radio signals for a distance OF six
miles, the wave length selected being
in 1919. experiments with fifteen meter
waves were made at Carnarvon.
After overcoming a few practical diff
hculties very strong and clear speech
was received at Holyhead. twenty miles
away" Mr.. Marconi added. "As a result
1t was decided to carry out further tests
overland across distance of nine.y-nine
miles between London and Birmingham.
1t was proved at once that with reflec-
tors at both ends good and clear speech
could be exchanged at all times between
the two places"
This is q record In long distance radio
transmission and reception with short
waves.
SearchIight and Lighthouse.
Mr. Marconi stated that the reflectors
make it possible for the receiver to re-
produce radio telephone song or speech
about 200 times louder than is ordinarily
possible. What Is more, speech is trans
mitted practically without distortion.
and the transmitting aerial can be used
both for sending and receiving at the
same time.
I'm these days OF broadcasting It NAV
still prove to be very useful to have a
practically new system which will be to
very large degree secret when COM
pared to the usual kind of RADIO" Mar
conf said, He added that the broadcast
ing stations are like the sun they radi-
ate In all directions. His own new sys-
tenn Is an out and out searchlight. 1t
confines radio communication to practi-
cally one direction.
Mr. Marconi believes revolving reflec-
tors would enable him to reaize an idea
that he first proposed twenty-six years
ago-the idea of a radio lighthouse which
will guide ships at sea during fog off
dangerous coasts. The transmitter and
reflector. revolving. act as kind of
wireless lighthouse or beam. and by
means of the revolving beam of electri-
cal recitation II is possible for ships.
when within certain distance, to ascer-
tain in thick weather, the bearing and
position Of the lighthouse" he said In
one test that he had made steamer
was able to take her bearings within
a quarter of point of the compass.
He thus forecast the possibilities OF the
reflector system:
at seems to me that It should be pos
sible to design apparatus by means OF
which a ship could radiate or project a
divergent beam of the short wave rays
In any desired direction, which rays, II
coming across a metallic object. such as
another steamer. would be reflected back
to a receiver on the sending ship and
thereby Immediately reveal the pres
ence and bearing of the other ship In
fog or thick weather. One further great
advantage of such an arrangement would
be that 1t would be able TO give warn
ing OF the presence and bearing of ships.