The picture opposite is one of those sent by the A. T. & T. Company on
May 20, 1924, by wire from Cleveland to New York. Some of the pictures
sent were from photographs taken earlier, and some were taken only a few
minutes before being transmitted.
In the sending machine, “the film picture is inserted in the machine
simply by rolling it up in a cylindrical form and slipped into the drum.
During operation a very small and intense beam of light shines through
the film upon a photo-electric cell within.”
In the receiving machine, “the sensitive film is put on a rotating
cylinder and turns like the cylinder record on a phonograph. On this
film falls a point of intense white light varied constantly.”
For synchronizing “two separate currents were sent over the wires, one
is called the picture channel, the other the synchronizing channel.”
“Forty-four minutes elapsed from the time the picture was taken in
Cleveland until it was reproduced in New York.” (_New York Times, May
20, 1924._)
It seems unlikely that returns from the daily wire transmission of
pictures can equal the day-by-day revenue from the wires used for the
transmission of speech when balanced up for the principal circuit,
phantom circuits, and carrier circuits.
[Illustration: [Photographs]]