The Bossier banner. [volume] (Bellevue, Bossier Parish, La.) 1859-1952, 1888-10-11
AERIAL PHOTOGRAPHY.
An Ingenious Process Recently Patented
by q Chicago Artist.


An Ingenious Process Recently Patented
by a Chicago Artist.
During the war of the Rebellion,
while the contending armies lay so
long between Richmond and the Poto-
mac, various efforts were made by
Northern engineers to obtain photo
graphs from aerial elevations of the
positions of the Southern troops. Tho
attempts were made from balloons, but
they were far from being successful.
The art of instantaneous photography
had not been pefected, if indeed it had
oeen more than thought of, and the
Danger of exposure to the almost un-
srring rifle of the sharpshooter was so
great that few were willing to essay
the operation except upon the most
favorable conditions of wind, weather
and situation. During the Franco
Prussian war, a few years later-par-
ticularly in the neighborhood of Paris
both French and German scientists
undertook the enterprise of securing
photographs of the opposing hostile
camps and movements, but only with
partial success. Since then photo
graphic departments have been at
tached to nearly all the European
armies, and numerous discoveries have
been made in the management of bal
looms at elevations of from 5000 to
10000 feet
M. j. Steffens, photographer of this
city, has recently secured letters
patent for a new system of aerial
photography, which promises to be of
value both for military and CONNER
cial purposes. 1t is a combination of
instantaneous photography controlled
by electricity. and hydrogen-filled
balloon capable of supporting weight
of not more than thirty or forty pounds
at an elevation of 5000 or 10000 feet.
| The balloon is composed of a film of
pure rubber, something like that used
in the manufacture of the little toy
articles which street fakirs sell at a
nickel apiece, and is filled with hydro
| gen gas made from the decomposition
of zinc by sulphuric acid and passed
| through bath of sillicate of soda, so as
to remove all traces of oxygen. To the
balloon is attached the camera, the me-
chanism of suspension being arranged
so as to allow of angular or rectangular
field of vision. Between the balloon
and the camera is a wind-fan to re-
duce oscillation to q minimum, and to
keep the camera in the desired position
an ingenious arrangement has been de-
vised whereby it will remain constant
in the arbitrary relation in which it
was placed to a large compass which
was delicately adjusted to it. The
camera is constructed somewhat upon
| the general plan of those used in TAX
ing photographs of horses running at
full speed, and the delicate machinery
for making the exposure and moving
on the rollers the sensitized paper is
manipulated from the ground by the
operator through the means of an or
binary telegraph key. The cord by
which the balloon is allowed to ascend
/ has within it two fine threads of cop
per, which are not allowed to touch
each other. On the ground, connec-
ton is made with a battery of three
or four cells, or as many as may be
needed. All that the operator has to
do is to insert roll of fsensitized paper
in the camera, adjust the angle oi
vision and the relation of the camera
to the compass, attach it to the balloon,
and then let it go aloft to the height
required. A click on the key causes
an instantaneous exposure; the ma
chinery in the interior of the camera
at the same moment begins to operate
and when the exposure is completed
eight inches of the sensitized paper
/ on which the picture has been taken,
is transferred to q second and smaller
roller in the opposite side of the camera
The instrument is then ready for 8
second view, and so ON until the sensi
tfzed paper-a roll Of forty or fifty feet
has been used, if so much be re
| quired. The apparatus is then hauled
down, the gas expelled from the bal
loon, and every thing used in connec
ton with the experiments packed
away in a box not much larger than ar
ordinary valise. The lens used is o
the globular variety-a recent inven
tion-and will take picture withou
any disturbance at any distance be
yond focus of seventy feet. At al
elevation of about $500 feet, the lem
having a visual angle of 60 degrees
the field of observation would be I;
circle having diameter of one mile
IF agreater field of observation wer,
required at the same height it woult
become necessary to use a lens having
a greater visual angle than so degrees
Chicago Tribune.
Miss Multum Don't you find |
very hard to catch Mr.. Warden's ex
preston, Mr.. Soleypn Mr.. Soley
(who is sketching the lawn tennis
party)-"Just about as hard as it is t.