, 1886-10-06

HOW OPTICAL ILLUSIONS ARE PRO-
oucED IN PANORAMAS.
what the Painter Has to study Care
fully In Order To He successfnl-How
the Most Critical Eye Is Dec-lved-Tho
Senses Require Training.

fully in Order To He successfn1-How
the Most Critical Eye Ia Dec-lved-Tho
Senses Require Training.
~To learn to see, doctor Is not the
sense of sight natural" exclaimed the re-
porter In surprise. The o~culist, who had
been charging upon optical delusions, re-
piled with n smile:
sounds queer, does 1t nots Well, the
sense of sight is Unborn to "A certain ex-
tent. but then so is walking. Still, If the
child does not learn to walk 1t will never
be able to do it. The eye undoubtedly
acts quicker and Mt an earlier stage ia
life upon exterior things, and is one OF the
first means to enlighten the growing
piece of humanity about the world. yet II
must be trained to do its work well. In
other words. man has to learn to see as
well rs to walk. The eye is the busiest
organ In the human economy. II does not
only inform the intelligent conception
about space and time n atmospheric
conditions and gravitation-to a certain
degree 1t represents sound, for reading is
nothing else than hearing With the eyes.
You see the words and their sound is
mentally present to you. 1t Is certain
that external impressions are at first al
together indlstinct to the new born babe;
1t has not yet learned to make mental
notes OF the picture on the retina Of it's
eye. But then the impressions of tou CHI
and movements go hand in hand with the
impression of seeing things, and by and
by the child distinguishes what is within
and without, on sop and below, right and
left. Tho perception of distances is one Of
the last things the eye learns to under
stand, but still the best-trained eye is fire.
quently subject to optical Illusions in the
matter of distances.
A MoDERN PANORAMA.
you enter a modern panorama and
your eye--that is, your sense Of seeing
is almost forced to believe in the reality
of what you see. You ooh in an almost
endless horizon, upon the episodes of a
battle between thousands Of men, many
of whom you recognize; you are moved by
the dying moments OF one MORALLY
wounded; you are enthused over the cour-
age OF the advancing troops and feel like
jun ping over the barriers into the SEEM
ing llmitless plain to be closer to the
scenes of battle. You see in the fore
ground the ~knapsacks, muskets, guns,
the withered vegetation, the undulating
ground, and far, far In the background
the line where the horizon and life JON,
cutting off from sight what is beyond.
Everything is SO natural, SO realistic.
For awhile you try to fix the line be-
tween body and space, reality and pict-
ure, out You soon give it up and are salts.
fled with the illusion. You do not even
think of the quietude Of the surround
ings, the mysterious stiffness which rests
over the fighting armies, the burning
buildings, and the laundering cannon.
The optical illusion is complete.
"There are so-called local signs in SIGHT
which the painter of a panorama picture
has to study carefully in order to be sue
cessful. First t, the eye brings the sizs of
the impression upon the retina into pro-
portion to the distance; then the lens ac-
commodities itself to the distance; then
comes the color perspective-distant arti-
Giles being indistinct, the nearer ones
plain; then the comparison of the object
TO be seen with objects intervening. II
you, for instance, compare a distant tree
with one near Mt hand, you do not calcu-
late upon the size OF the former actually
seen by you. but compare 1t mentally
with the size of the one next to you.
AFTER sENTuRIEs OF FFoRT
The first artists painted things as they
thought them TO be-thut is, as they
would be able to perceive them by The
sense of touching. After centuries of eff
forts the dimension and color perspectives
was invented, and the effects OF these are
employed In the panorama with great
shrewdness and very subtle observation OF
nature. The perspectives of dimensions
and colors are so calculated that the OBJ
server has little or no measure for reality.
The canvas is MS far removed from the
eye of the observer as possible, and conse-
quently the eye Is compelled to accom-
modate itself to distance. an operation
which requires mental work and impairs
criticism. There Is no frame to the pict-
ure, and In stretching the canvas care il
taken to avoid any creases which would
offer n point OF vantage to the eye.
1.-The objects Intervening between the
eye and the picture are of natural size.
but carefully chosen as to diameter and
position; the ground is sloping and the
connection between these real objects and
the picture is so arranged that the en-
semble is not disturbed. The spell of the
illusion might be broken should one step
directly from the street in front of the
picture, so that his mind would be filled
by n lively remembrance of the reality
without In such a case it would take
time before the eye accustomed itself to
the Illusion. But then you have to pass
through darkened CO rridors and narrow
passages, dimly illuminated by artificial
light, before you come into the panorama
proper. These changing impressions de
stroy the Inst remnant of the scenes OF
reality offered on the street without, and
after the FIRST glance at the picture the
illusion is complete. n-Chicago News.