The Black Hills union. [volume] (Rapid City, Pennington County, Dakota [S.D.]) 1889-1904, 1896-06-05
Journal.

AlS1lS, CaJD IL LNSW
York Journal.
There is something strongly sugges-
tive of Jules Verne's observation cham
Der of the Nautilus in the device en-
ployed by the ingenious photographer
to give to the world the first scientific
knowledge on this most interesting sub
ject. He has made us acquainted with
the denizens of the deep in all of their
p~eculiarities. ACKNOWLEDGEMENTS"
is the name given by it's %discoverer to
this new form of photography. BY it
he has been enabled to examine not
only the motions of cells, sharks, toads,
ETC., but also very small marine ami
mails. This was originally a matter
of extreme difficulty, as a brilliant il
Elimination, not to be had with an ordi-
nary aquarium, was necessary. To
remove this obstacle, M. Marcy had a
special apparatus made, which, to a GER
tain extent, made his work much easier.
This crude contrivance was nothing
more o less than an aquarium, with
front and back glass sides, which was
placed in an opening made in the outer
wall. The light, therefore, penetrated
the darkened chamber through the me-
dunn of the transparent glass sides,
separated by the semi-transparent
water, in which the fish were swim
ming. This arrangement gave the fish
the appearance of ~silhouettes against a
light background.
After devoting considerable thought
to the subject, M. Marcy finally hit up
on another scheme. This was to place
the aquarium somewhat lower than the
opening and provide it with an opaque
trap, or leaf, which could be swung up
when it became necessary to illuminate
the aquarium in the manner first men
toned, the opening above being en-
tirely closed. Thus the light at the
back is completely shut off, and the
rays, entering from above, are reflected
downward to an angle of As degrees by
a mirror placed above it. From thirty
to fifty exposures a second were then
made by the Photographic apparatus,
which was placed in the dark oom be-
hind and opposite the aquarium, in
such a that the occupants were
in the field of the objective.
The negatives are made on flexible
films, a roll of uneXposed films being
placed in the camera, the free end OF
which is secured to a second roller, so
that when the latter is set in motion,
the film is rolled upon it, and unrolled
from the other. The exposures, how
ever, must be made during the unwind
ing of the film. No matter how rapidly
the exposures are made, the film must
be perfectly stationary at the instant.
and an arrangement is provided by
which the film is held fiat against the
plate of the roller holders during the
exposure. Motion is communicated to
the roll by means Of clockwork, which
at the. same time rotates the disk by
which the exposures are made, openings
being made in the disk, and when, in
the course of a revolution, one of these
comes opposite the objective, an expos
ure is made.
During the rapid movements of the
film, which traverse thirty-two inches
a second, it has to be held sta
tionary forty or fifty times. In order
to avoid tearing the film it passes over
an elastic, flexible plate, just before it
is wound upon the roller. The Mate
gives the instant the film is arrested in
it's motion and springs back again as
soon as the same is released. Exposed
rolls may be removed and fresh ones
substituted in broad daylight.
In photographing the movements of
jelly fsh-which, by the way, are trans
parent-only from ten to twelve pic
lures were taken, this number being all
that was necessary, owing to the slow
ness of the medusa's movements. The
exposure was made with the illumina-
ton coming from above and against a
dark background. Twenty exposures
a second. however, were necessary in
reproducing the movements of the sea-
horse, whoce actions are both rapid and
undulating.
The Investigations of marine life, as
conducted by NJ. Marcy through his new
inventions, are as interesting to the
piscatorial branch of the scientific
world as are Prof. Roentgen's to the
medical department.
The Voice of the Nineteenth Century.