The citizen-Republican. (Scotland, Bon Homme County, S.D.) 1???-19??, 1913-08-28

COLD LIGHT.
From the Amateur Photographer

from the Amateur photographer
PROFESSOR Charles Dussaud, of Paris "a
pioneer of wireless biography, has re-
Gently given a demonstration in London of
what threatens to be a veritable revolu-
ton In lighting-power, which will be of
particular interest to Photographers. BY
ITS use the production OF heat in the use
OF electric light in lanterns and kline
autographs is entirely avoided, hence its
itle cold light" At the demonstration
ne proved conclusively, by experiment,
that the light could be enclosed in a, pro-
lecting lantern. with paper as a substi-
tute for Russian iron, without the slight
est risk of overheating and fire. He also
showed that such interesting objects as
the interior of the human mouth and
shroat could, by its means, be projected
On to a screen for demonstration or other
purposes In their natural c%oloring without
the slightest Inconvenience to the owner
from the heating Of the Tampa tiny thing
an inch or SO in diameter. For lantern
lists the special advantage was shown to
DE that ~lantern-slides made of film could
be safely used in place of glass, thus
avoiding the of weight, ex-
oense, danger of breakage, and difficulty
of conveyance.
The system is a highly ingenious one.
and 1t combines with the absence Of heat
IN enormous increase In l~ighting-power.
To be strictly unscientiic, everyone knows
that If a lamp is attached to a higher
voltage than that for which 1t is made, 1t
gives a fine increased light for a short
time and then bursts. Professor Dussaud
attaches an ordinary four-candle-power
lamp to double" the voltage for which it Is
made. and it gives at once a 100 CANDLE
tower light; nor does 1t burst, or ever
grow warm. He obtains this end by in
terrupting the current. This can be done
with a single lamp by cutting off the cur
rent for the fraction of a homer n
then restoring II. and repeating this OPP
grafton; or, better still, by using three Of
the small lamps revolving, so that each
touches a contact inc is lighted, and
then has a double period of rest, during
which such fraction of heating, If any,
as 1t has received is cooled out and lost.
So far as the eye can perceive the lighting
is continuous. Actually, the three little
lamps are revolving. One is lighted, is
revolved past the point OF contact. and
the next then CLOVIS in its place. The inn
lnense increase in lighting power Is OBJ
tanned without any increase in con-
sumption. The advantage of this to the
lanternist should be incalculable, and the
.densest color-slides should be showable
from the ordinary domestic supply. It is
claimed that, by the use of this non-heat-
ing light, celluloid may be safely utilized
in the kinenlatograph. Moreover, the light
can De produced from q very small%bat-
terry or accumulation, and therefore in an
unwircd building. It was quite a revolu-
ton in itself to see a tiny lamp in work
at the demonstration, showing brayely a
colored slide in a four-yard circle on the
screen, and shaming by Its performance
an arc lamp in a yantern double Its size
on a neighboring table. A special advant-
& of this system for the kinematograph
should be that by Its use the film can be
stopped at any moment for demonstration
or other purpose ad lbitum.