The morning call., 1891-04-05

obtain representative types for scientific
purposes. For example, composite was
made of a number of murderers' skulls IN
order to see if there was anything typical in
their development. The same thing was
tried with the skulls of savageS, as we'll as
with those of people of certain professions.
the idea being to find out whether the
moral nature or mental training OF the man
produced any definite cranial modification:
So far as is known, nothing was ascertained
very decisive:
photography lately for the purpose of find
ing out what sorts of lamps gave the great
est amount of light. Pictures were taken
question. Copies of these are to be sent TO
lighthouse keepers to show them what
shape of flame, naturally depending upon
the cutting OF the wick, is most desirable.
For some time past the microscope has
been utilized in very interesting ways for
greatly enlarging small objects by ph0tog-
Taphy. The end of the instrument 10 which
the eye is ordinarily applied is introduced
into the cameras dark chamber, while
ray of light is thrown by a small lamp at the
other end through the object glass. on
which the thing to be pictured is placed
and through the tube of the microscope,
thus casting the image of the object upon
the sensitive plate at the back Of the camera,
which stands exactly in the relation of the
RETINA IN THE EYE OF AN OBSERVER.
In this manner small sections of rock. cut
so thin us to be transparent, are photo
graphed so as to show the material CT which
they are made up. By the same process the
finest silks and linens are depicted on
greatly magnifed scale, so that they are
made TO look like SO much coarse mating,
their warp and wOof being as plainly dis
cernibie as if they were so much straw
plating.
Perhaps the most extraordinary applica-
ton of photography that it is possible to
mention is found in the multii0rm mechani-
cal processes used at the present day for the
reproduction or pictures. La the illustrating
OF magazines the art OF wOOd-cutting has
been almost entirely superseded by photo
engraving IN one shape or another. Until
recently 1t was thought impossible TO repro
duce III this way anything but a draw
Ing composed of lines but now even
painting can be copied oif-hald in the shape
IF cut by the simple device of placing
gauZe screen betW cen the picture and the
camera, the network OF the gauze breaking
up the solid lights and shadows so as to
make them reprOducible. A much better
way of accomplishing this, however, has
been lately invented, by cutting cross lines
on the glass negative itself. Thus you find
in the newspapers of to-day most beautiful
engraylngs of actual works of art, done
within a few hours, which would have taken
the hand workman not long ago months to
turn out.
Art photography is making rapid strides
ahead. The more advanced workers in this
line are producing results, shown at exhibit
tons year by year, which vie with the
painters best execution. Some of them
even form actual Photographic compost
nOnS by combining IN one picture back
ground with suitable foreground from
another negative, figures from still another,
HtRaA-
Expert Photographer Smills of the Ma
tiOnai Museum, who knows more about this
branch of art than
ANY OTHER MAN IN THE UNITED STATES,
Is getting together an exhibit which will in
clude picture by every Photographic pro-
cess ever devised, with the apparatus for
making it.
In the latter half of the sixteenth century
Giovanni Baptiste Porta, a Nedpuiitan
physician, Invented the camera obscura,
which may be said to have been the origin
Of photography. 1t was simply a dark
chamber, through a small hole in which the
rays OF sunlight projected upon screen
within picture of whatever was in front.
The use originally made of it was to copy
pictures, which. being thrown upon a
screen of canvas within closet where the
artist sat, were readily gone over with paint
and brush, the very cOlOrS being reproduced
in the inverted image. This was almost the
art. In the year 1850 a fantastic writer
named De Ia Roche, a Frenchman,
published an imaginary interview with
devils, which, unknown to HIMSELF was
marvellous prophecy. He related how he
was caught up in a hurricane and deposited
in the domain of the Genii, who initiated
him into the secrets of nature. One genius
he quotes as saying: You know that rays
of light reflected from bodies form pictures
upon polished surfaces; for example, on the
retlna Of the eye, on water and on glass.
The spirits have sought to Tx these heeting
images. They have made subtle matter
by means of which picture is formed in the
twinkling OF an eye. They coat piece OF
canvas with this substance and place 1t in
front of the Object to be taken. By means
Of its viscOus nature the prepared canvas
retains j
FAC-SIMILE OF THE MAGE
Instantaneously. Finally, the canvas is
deposited in dark press, and. when it is
dry, there Is picture so perfect that no arr
can initiate its truthiulness."
In III Scheller, the great Swedish chem
ist. who had situated the action OF light upon
chloride OF silver, made a photOgraph-the
first ever prOduced-0f the solar spectrum
by projecting the latter upon a sheet of
paper busted with silver chloride. Twenty
i've years later Dayy and WedgwOod, in
England, obtained an impression of the
solar spectrum upon paper prepared with
salts OF silver, but were unable to make il
permanent In 1924, Joseph Niepce made
the first permanent Photograph with
plate covered with asphaltum, a esnous
matter extracted from petroleum aud much
used at the present day for payementS. Two
years later Niepce went into partnership with
Daguerre, and they continued the expert
ments, which resulted in the daguerre0type.
Among the apparatus Illustrative of photo
graphic history to be shown at the Ma
tional Museum before long is the first camera
ever made in the United States, which was
constructed here by friend of Daguerre.
under the directions Of the latter, before his
process was made public. Accompanying
this are two boxes of the original silver
plates made for the purpose, unused.
RENE BACHE