The times. [volume] (Richmond, Va.) 1890-1903, 1900-06-06
STILL REMAINS A
THING UNKNOWN
The Actual Color Photograph Not
Yet Realized.
PROFESSOR JCLY's EXPERIMENTS
The Irish Scientist Has Made the
Most Progress III This Art and
Good Results Have Been
Obtained.
PROFESSOR JCLY'S EXPERIMENTS

What progress has color printing by
photography made In the last decade?
That is the question which camera artists
are asking each other.
Those most advanced in the art OF pict-
ure-coloriug ty machinery will answer
YOU, '.nothing.'' Color work IS still done
upon mechanical presses, by the process
of photo-engraving, assisted by other
arts, but the actual color photograph
is still a thing unknown
MANY have been the attempts at color
One process, the Jolly. has SucceSoeo
fairly we'll. OF this process j. Stewart
Gibson says: professor John Jolly OF
Trinity College, Dublin. is the inventor
of a process of color photography which
has excited considerable interest He
thus states the problem: Composite
color photography deals with the subJec-
tive reproduction of all visible wave
lengths in two stageS-a Photographic
analysis and an optical sEntheSls. III
the first operation the seVera! wave
lengths are caused to produce three sepi-
rate Photographic images, according TO
their physiological activity in exciting the
supposed fundamental red, green and VIC
let sensat lions The method consists in
the practical application of this principle
in connection with another physiological
princ!ple-viz.. the equivalence OF Jux-
taposition and superposition OF colored
light when comprised WITHIN q Su4lciehtiS
small visual angie
SCIENTIFIC EXPLANATION
"The equivalence of juxtaposition and
s11nernosition under certain conditions Is
innortant It is a well-known fact that
the superposition of red and green 4lSAl
is recognized as yellow by the eye; ana
that similar results occur Wiih other
superpostions. The reason for TINS IS
quite apparent after a little study OF the
svntllesized spectrum Now, the Jlsla-
posing of the same colorS will give the
same derivative, providing the juXtaposi-
ton is properly made
I'm the Jolly process this is accomplished
by placing the coiors in narrow bands .
side by side. 1t has been demonstrated
that when the three fundamental coiorS'
taken all together. or by twos or s!nsly,
in various proportions. are juxtaDosed ana
presented 10 the eye so that the comblna-
ton occupies visual angle of not more
than one minute of arc, the colGrs are
synthesized and the complex color sen
sation produced is the same as that result
ing from superposition
fact will show that for transparency
viewed at a convenient distance upwards
of 600 lines per inch will be required in
order to synthes!ze the color perfectly
In showing such a picture with the
magic lantern it is evident that these
conditions with a reference TO the VISUAL
angle must be observed
In other words, the learned professor
would have US know that he takes pho-
tographs in their natural colors, after
process which in its scientific explanation
seems difficult, but is much easier: when
actually applied. The familiar half-tones
are done, actually somewhat along these
lines.
Not long ago the Photographic world
was startled and pleased at a photo
graphic exhibition OF colored pictures
alleged TO have been taken with the cam
era The process remained a secret with
the inventor, but the pictures We're exnln-
tied in New York city This process
required its own ptate-a remarkable
plate, by the way, and one seemingly
endowed with All intelligence OF its own
GOOD RESULTS
The process by which these photographs
are made is the development of one sug-
gested first by DR.. Adrian Dansac. 1t
soon attracted the attention of English
men Of science, and the process is az pre-
sent regarded as the one that has long
been sought for-that is. il makes a
photograph which possesses the colors Of
the original object.
A plate that has been submitted 10
certain treatment is used. and after that
The exposure ana UeVetODHlSNl are accom-
plished in the same way that they are
when an ordinary photograph is taken
There is no trace OF color in the picture
up 10 this stage, nor is there after the
print has been made on either g-aSS or
paper. The glass or paper has also TO
be submitted 10 this especial trea tnent
The media That produce the color are
applied afer the print is finished.
Four liquids are used for this. One
+ is colorless, and the other three are blue,
green and red. The colorIess liquid is
applied TO the print with d camel s-hair
brush. It Is supposed 10 give the print
] the seIective power The blue, green and
! red are successfully applied, with an
| application OF the colorless liquid between
| every use of the blue and green After
J each application the print is wiped dry.
| From the blue. green and red solutions
| applied the print takes the colors OF the
| original. although none OF these three
may have been separately present IN the
| original view.
/ The pictures, which were brought from
| Paris for the exhibit, covered nearly every
| field. and particularly in the landscapes
done on glass or ground glass the effect
/ beautiful There were several portraits.
and one of these was a woman IN gray
I iiaiEing-areE5. Every shade in the cos
| tune. as wei! SIS the fiesh-tats and the
| flowers on the hat. was reproduced. The
| cape was OF ctirchilla fur. and the bodice
/ was of pink, covered with black tu,le.
! The mink showed plainly, Just as did the
sda1icate-colored ernbroideries on the tulle.
A view of the Jardin d'Acclimation in
/ Paris showed a group of storks behind
| = wire fence, and the reddish colordnS Of