Indian chieftain. [volume] (Vinita, Indian Territory [Okla.]) 1882-1902, 1888-10-11

The subjoined article Is one OF the
last written by Prof Richard A. Proc
tor for the Philadelphia Press previous
10 his recent death by yellow fever at
u New York hospital.l
"Secing Is believing" says the old
proverb. but "seeing is deceiving''
would be nearer tha mark. We are
/ deceived By false impressions even
hen we know the real state OF the
N 1se, so that nature may In some sense
ve compared with conjurer who ex-
plains the trick he is about to play.
yet deceives the eye as perfectly as
though we knew nothing about the
manner Of his performance. We know
that the handkerchief which we gave
him TO experiment upon has not been
cut in half. yet we saw him cut il
in half; we know he has not pounded
our gold watch in mortar, yet that is
what we saw him do.
Here is nature about to perform her
daily conjuring trick OF making the
sun, as he sets. look larger than he
out OF shape, because nature uses APP
paratus TO produce that illusion, and
the eye really does see correctly. But
fhe makes the sun look swollen and
huge without apparatus, though again
and again we find her clever perform
ance explained in that way. The
kindly instructive persons who wrote
"Sandfords and Mertons" for the con-
fusion of intelligent childhood, care
fully explain that IL is the refracting
power OF the air which enlarges the
setting sun, even as the refracting
power OF water in glass bottle en-
larges letters seen through IL. But the
refracting power of the air has nothing
10 do with the apparent enlargement
OF the sun. II does affect the suns ap-
parent size, but the other way,
making him look smaller not larger
in just such degree as IL apparently
congresses him from globe TO an
egg. Nature simply takes us In when
she makes us believe that the
setting sun looks larger than the sun
in the midheavens. Nature deceives us
by making us think tile sun IN the
midheaven looks smaller than when
near the horizon. Perhaps the reader
thinks the statements identical. But
they are not We are nearer the truth
when we judge the suns size as he
nears the horizon than when we osti-
mate II from his appearance high
above that circle. The reason is OBJ
viOus. When the sun is low we can
zee by the aspect Of the landscape
that he is much farther away than yon-
der house or hill or tree than when he
Is actually on the horizon. We see
that he Is behind those objects, and
thus We can not imagine him to be
merely foot or yard in diameter, be-
tween which lengths lie all the esti-
mates OF the suns diameter, which
the mind unconsciously forms when
he is high in the sky. SO he seems to
DO much larger when low.
BUt just here tho thoughtful reader
will perhaps urge that the eye ought
still TO be able TO judge whether the
image Of the sun in the visual field is
'oally no larger when he is low. The
eye, however, knows nothing about
its visual field. The mind judges Of
what tho eye secs in quite other WAYS
Here is simple experiment 10 show
this:
In good black ink draw capital
lotter-preferably round o in strong
black type on white card Now, sit
ting facing a wall Of uniform tint, hold
Or fix the card steadily in an upright
position at about arms length and
contemplate that black o as steadily
as possible, ''while one with moderate
haste may count hundred" Now let
the card drop and look at the wall
with Ms little interruption in the time
'nd as little change in the diameter Of
vision as possible There is seon as
Usual the Complementary image OF the
letter, but IL has grown much larger.
IT, for instance, the o is an inch in
diameter and the wall Is twelve times
ms far away as the card bad been, the
letter seen will be apparently a FOOT in
diameter The mind is not able 10
persuade itself that the latter has not
grown suddenly larger, Yet in reality
tle image In the visual field IS pre-
cisely the same now as IL had been be-
fore. The mind is simply deceived by
The effect OF distance-the same OBJ
ject seen Of the same apparent size,
but supposed to be at greater dis
tance, is judged 10 be larger.
SO il Is with the setting sun. The
eye sees that the sun Is far on. and
10 judges him 70 be largo. though
ihe area Of his image in the visual
field is no larger Qndeed measur-
ably smallor) than when he is high
above the horizon.
How Is II, then, the reader may hero
nsk, that the apparent enlargement OF
the settling sun and moon varies with
The condition OF the air? The setting
or rising moon, IN particular, looks
much larger when the ain. Is thick.
Does this not prove that the refractive
action Of tho air is In question: The
effects OF the refractivo action OF the air
being perlectly we'll known no r.henana-
ena whatsoever can provo that that
ncsion does what itis not capable OF do
iag. Tho explanation Of the effects OF
thick AIR is very simple. The sugges-
lion Of increased distance already
fiFona when he eEn at noon q Low. Is
strengthened 4 ihs mir II thick For
tlsc sun gud moon thon look fainter
Fpe lee lnlua recognizes ~ fainter