The sun., 1917-09-09

circumstances would become gray. and
this transformation wrought by hight
and not pigments stimulated my
curiosity.
"The next thing was to awaken to
tho fact that my problem was not one
Of making grays IN the first place. but
Of associating colors-not mixing
them-so that the atmosphere would
eventually produce the effect Of dis
tance or low visibility. Rood showed
mo the way to my desired goal.
"As he pointed out. while the mix
ture Of yellow with blue pigments
produced invariably green hue Of
varying intensity, the mixture of blue
with yellow light gave q moro or less
pure white. but under no circum-
stances anything approaching green.
BY tintins sectors Of cardboard discs
different colors and then revolving
them rapidly Rood obtained astonish-
ing results. For instance. when half
Of tho disc was red. . little over .
quarter emerald green and the rest
ultramarine blue. these colors. when
spun. resolved themselves into beau
tiful pure gray. The same colors
mixed together As pigments would
give an entirely different result
ITO put It popularly. Nature vir-
tually works the rotating DISC prfn6-
pie upon us when she achieves
through tho medium Of the vibratory
! atmosphere = kindred effect
why Gaudy Birds Don't show.
"A disc colored half blue and half
yellow when rotated will resolve
itself into gray. while . vivid orange
and green disc will yield canary yell
low by tho same meanA Rood set for
me sure milestones along my search
for the underlying secret Of Natures
camouflage OF color. I realized then
why the green tree could 30 effectually
conceal the varie gated parrot. the scar
let tanager. the oriole the bluebird.
&c The green Of the tree was only
the dominant color-yellow and red
were there, though invisible to the hu'
man eye, to neutralize those gaudy
feathers. These latent colors como to
the fore in the fall.
These facts suggested to me thai
camouf1age for our ships should o<
based upon a color scheme we'll nigh
Numerically opposed to that hereto
fore accepted as the likeliest to pro-
mote concealment or low visibility. In
stead OF starting out with gray coa'
concluded that 1t would be much
better to use colors that were brigh
when viewed near by and upon which
the atmosphere would work the de
sired metamorphosis as distance in
creased. I had to bear in mind tina
the light OF daytime is not Of uni
form character: according to the hou
and the clearness of the air one or an
other of the three dominating colors o
the spectrum prevails AS Rood says
these are not the red blue and yellow
so long considered the natural pri
maries. but instead are red. grestl an'
violet"
An inkling of this invisible shift o
daylight color was given about twelve
years ago. when an observing instru
ment for n submarine built here 70
Russia was undergoing her tests. Th
} moment the periscope was swung to
ward the sun objects seemed to vihrat
and could he picked up only with diff
ficulty, and then through a rainboy
) haze that hampered Identification an
vision still more.
1t was suggested that II the observe
wore colored glasses matters would b
improved, and gray, blue and re-
glasses were tried. They prevented TIL
dazzling effect of the full g!are, and
was even noted that at times object
away from the sun stood out more dis
tinctly when seen in this way thai
when viewed by the naked eye. y
. one thought to analyZe these phe
: nomena, but they Surely pointed to tn
facts mentioned by Prof. Rood an
since confirmed by Mr., Mackay an
others.
How the y-D"nt Takes Aim.
1t is quite likely that the German
, have had to contend with the limita
tons OF periscopic observation, an
with their accustomed thoroughnes
, they probably have provided thci
U-boat commanders with means b
!, which they can look directly towar
a the sun and at a target lying in tn
path of the solar rays As a lOgics
, consequence the optical techniciar
! would likewise provide glasses of sue
colors as would tend to increase III
distinctncss of objects under differcr
conditions OF the atmosphere. This {
course is merely an assumption, hr
any really successful system Of ma
, rine camoufage must presuppose this
$ the enemy is able TO do this, for onl
e by anticipation OF this sort can th
a foes task be made difficult one at a
4 times. As Won Moltke said. It mul
Y always be assumed that the enem
i, will make the right move.
Any one who has looked through gu