The Dawson news. (Dawson, Ga.) 1889-current, 1910-01-26
PHOTOS TAKEN 500 MILES
TRANSMITTED OVER TELEGRAPH
OR TELEPHONE LINES.
remarkable Example of Long Dis
lance Photography Received at
John Hopkins University.

John Hopkins University.
BALTIMORE, Md.-Prof. Harry G.
Jones of Johns Hopkins University
has received some remarkable exam
pies of long distance Photography.
taken by A. Korn of Berlin, former
ly of Munich, who invented the pro-
cess. Some of the photographs were
transmitted to Berlin from Paris.
about 500 miles away, said Prof.
Jones, to The Sun Many of the
views are practically as clear as the
originals.
1t has been shown by the process
that photographs can be transmitted
distinctly over telegraph or tele-
phone wire for several hundred
miles. This feat is said to have been
accomplished number of times by
Mr.. Korn. 1t is probable, Prof. Jones
thinks, that it will soon be possible
to send pictures across the Atlantic
by electricity. One of the remarka-
bic features about the process is
that it takes scarcely ten minutes to
reproduce photograph in a city sew
eral hundred miles away.
The process may mean that in the
future illustrations of events in Eu-
rope may be reproduced in this coun-
try on the day of occurrence At
present it is possible to send pictures
between cities several hundred miles
apart.
The long distance photography is
based on the scientific fact that the
element selenium, which belongs to
the same chemical group as sulphur,
conducts electricity when exposed to
the light and when in the dark does
not do so. If photograph is wished
in Berlin of subject in Paris gela-
tine film of the subject is specially
prepared in Paris. This is rolled in
cylindrical fern and in the axis of
the cylinder is placed a bar of Sc
lenium.
All is placed in a dark box,
through which a beam of light is al
lowed to enter The cylinder is ro-
tated spirally so that as it rotates
every section of the cylinder will be
exposed an equal length of time.
The light passes through the trans
parent portion of the film and the
selenium becomes conductor. When
the light strikes the OPAQUE por-
lions it does not pierce the film. The
selentum is connected with a source
of potential of ITO volts.
The receiving end is even more in
teresting than the instrument used to
send the photographs over the wire.
A Photographic film is placed over A
cylinder and this is placed in a dark
box. This cylinder is made to rotate
in harmony with the sending cylin-
der The dark box at the receiving
station has small opening for
light to pass through and touch the
film. When the selenium is conduct
ing this shutter can be regulated so
that it will be either opened or closed.
AS the current from the selenium can
be regulated so that the shutter can
be opened or closed when the selen-
ium is conducting, it means that
either positive or negative prints can
be produced at the receiving end.
When the shutter is open the dark
parts of the image are made on the
film, and when it is closed the light
parts are made.
Professor Jones says excellent re-
suits have been produced by the pro-
cess. Mr.. Korn has another process
through which, instead of sending
halftone photographs, he can send
drawings of the photographs similar
to pen and ink drawings. Great in
terest has been created in scientific
circles over the invention.