The daily worker. [volume] (Chicago, Ill.) 1924-1958, 1924-05-22

PAOSO9A opus Wy WI u OAAO <AA4Cl ~
pany announced today that pict
month can be sent to news
papers for printing within a
comparatively few minutes after
the incident photographed oc-
ours.
Arrangements already have been
made for broadcasting the proceed
ings of both conventions by radio.
Successful Tests.
The experiments conducted by the
A. T. and T. resulted in Is photo
graphs being transmitted from Cleve-
land to New York within two hours.
The success Of the tests led to the
general conclusion that the work of
sending news photos by wire has now
reached such an advanced stage Of de-
velopment that it can now be placed
on a commercial basis.
Different kinds of pictures were
used for the experiment first, several
studies of President Coolidge were
transmitted, coming out with amazing
clearness and permitting first-class
reproduction in the morning New
York newspapers. Following these
was picture of the high level bridge
at Cleveland, bringing out clearly not
only the structure, but surroundings,
a tug boat and smoke from the boat
funnel. Pictures of e. c. Hopwood,
editor of the Cleveland Plain Dealer,
and H. B. R. Briggs, editor of the
Cleveland Press followed, each strik-
ingly clear in detail.
Invention Practical.
All were reproduced in New York
papers without finishing touches and
demonstrated clearly the practicable
ty of the invention.
The sending machine for the expert
ment was set up in Cleveland and its
operator was under the direction of A.
T. and T. engineers. The experiment
was witnessed by numerous newspa-
per publishers and reporters. The
general principles Of the process are
simple, altho there is an infinite
amount of complex detail. The basis
is a photo-electric cell which trans
lates every variation of beam of
light into variation of electric cur
rent, which in turn, is translated into
variation Of light at the receiving
end.
The source of light in the sending
machine is the same as an ordinary
automobile lamp. The spot Of light
from the lamp passes thru lens upon
Photographic film which, in turn, is
transmitted. The film is in the form
of cylinder, and as this cylinder re-
wolves, the point of light passes thru
the transparent film and falls upon
potassium pencil, which runs thru
the center of the cylinder.
This piece of potassium forms
high sensitive photo-electric cell.
When the light falls on it, the cleo
irons fly from the surface Of the po-
tassium, forming an electric current,
varying in intensity in accordance
with the shades of the picture repro
duced.
The fluctuations of the current from
Jn6 plOIO-eleCLrlC cell are Iueu iii
posed upon the direct current, which
flows thru the telephone wires. This
current is several billion times as
powerful as that caused directly by
the light, but the strong current is
made to reproduce every variation in
intensity.
The telephone people believe that
the development of their invention in
this field surpasses that of other ex-
periments by the Radio Corporation
and G. Francis Jenkins, Washington
inventor, who for several years has
been attempting the transmission of
pictures by radio. Telephone officials
explain that radio transmission Of
photos, while possible, is less prac-
teal because of the disturbances it
would cause and be subjected to in
the ether.
Use of telephone wires instead of
the air for such transmission elimi-
mates this difficulty, they point out.