Brownsville herald. [volume] (Brownsville, Tex.) 1910-current, 1928-10-05
CLOSEUP IS
BEST ON Wire
Detail and Contrast Is
Requisite to Good
Picture
BY HOWARD W. BLAKESLEE
(Associated Press Science Editorl

NEW YORK, Oct. 5.-tR-How
good is your photo-telegraph sigma
ture-and what is the best way TO
send your photo-telegraph face to a
friend?
These are questions which have
been taken out of the research lab
oratories and laid on the public's
show case, now that either mes
sages or pictures may be filed at
telegraph offices for wire transmits
sion. The answers given here have
been gathered from the photo-trans-
mission laboratories Of the tele-
phone and telegraph companies
which are doing this work.
II you signature Is done in a big
masterful fist" it is not altogeth-
Ell good for photo-transmission. The
big sNaature can be sent just as
readily as any other. but not with
out cutting out some Of the space
available for other information in
the same message. For the photo
telegram is limited to what may be
set down clearly on a 5 by z inch
photo. That is much when type
written, but many a sample Of
eh~irography would not do 20 we'll.
For your photo-telegraphic face,
IL your purpose is to give n very
clear idea Of your appearance. the
file should be a closeup, prefer
ably with the lights and shadows
well defined. that is. not too much
of the twilight effect. But II some
necessity compels sending your face
whan ynr do MT rura nhnTf hmr-
ing its details too distinct, then file
a picture which has plenty Of back
ground, such as relatives. friends or
trees or group photos. and be sure
TO specify that the background be
included in the wire transmission.
This again is all because at the
present stage OF development 8 by
z is the largest size transmissible.
and the moving finger Of light which
paints this wire picture can do Won
ders with large figures close up, but
not so much with details that are
too small.
Two fingers Of light, one in the
sending city ard one in the recelv-
ing city. with an electric current be-
tween them. do the photogram work.
An ordinary photo is first made Of
the message or picture to be sent.
This photo is developed on trans
parent celluloid film. which is roll
ed into cylindrical form about the
size of an old-fashioned photograph
cylinder. This film is revolved.
with a tiny beam Of light, one one
hundredth Of an inch square. shin
ing through il. The needle Of light
passes owe the cylindrical film un-
til il has scanned every part Of the
surface.
This beam is bright or dark aft
er il penetrates the film, according
to the objects in the picture. "A
photo-electric cell catches the vary
ing light. changes IL into an electric
current. the current is then ampli-
fled about s times. and transmitted
by wire to the receiving city. There
another tiny light finger scans an
: other cylinder. but this time the
cylinder is an uneXposed photo
graphic film. The receiving light
passes through a small aperture
which is opened or closed by a rib
bon. This ribbon receives the cleo
trical impulses from the machine in
the sending city, and they cause Il
TO vibrate. The vibration permits
light 10 pass through the aperture
and fall upon the ~unexposed mega
tive in the exact proportion or the
light from the original picture.
which is thereby reproduced.