Evening star. [volume] (Washington, D.C.) 1854-1972, 1911-02-19

Emerald green Is.
Dark brown. .........--.- Is.
Verm1l1On IL.
Black paper O.5
Deep chocolate DAG
Black velvet .-..-...... VA
Must Have Overhead Light
Ply the laws of evolution the human eye has
= become accustomed to sunlight, or sky
light, coming obliquely from above, and our
eyes resent light coming from any other
source. Snow blindness, distress from white
sand or water, is the result of violating this
rule. The upper eyelid is adapted to shade
the eye from strong light from above. The
lower lid cannot perform this Office; SO when
a strong light is reflected up into the eyes it
blinds us. Blackening the lower lid will eff
feet cure. And the eye is also grown used
gray, hazy, or foggy day is very firing to the
eyes On such days the light seems to come
from nowhere in particular.
The iris diaphragm of the eye is capable of
adjustment to various degrees of illumina
ton. Quick as this membrane is, it is not
instantaneous; therefore, if we pop out of
the dark into well lighted room, it will be
sometime before we can see at all. This
iris adjusts itself to cope with the brightest
light it has to encounter; therefore we fail to
see beyond the powerful searchlights of an
automobile, while after the machine has
passed we can see for long distance.
The eyes have only certain range, weak
enough at best. AS all know, there are
plenty of times when all appears black to us,
and vet the horse can see the road and the
cat hunts along the hedge. The trouble is
that the faint light rays move too slowly to
be registered on the human retina. The X
ray has proved beyond doubt that there are
light rays which move too fast for human
eyes to register. This light penetrates
books, wood, paper, and even human flesh.
With the microscope to assist our eyes, we can
see the bones in our arm without bothering
to remove coat or shirt. But man with x
ray eyes would be sadly handicapped in this
world; for he could see nothing but solids,
such as earths and metals, and would be
unable to see board fence at all. Beyond
doubt there is light SO bright that the eyes
cannot see it, and to us all is darkness be-
yond what our eyes will register.
Totally Dark In Space
T IGHT rays themselves are invisible. When
- they move through the ether alone our
eyes cannot see them; consequently all is total
darkness. But when they meet with the
resistance of our atmosphere, producing
heat, they register on the retlna and-be-
hold, we can see! AS the atmosphere thins
Tdp1Qly as we 90 upWdIu, 81 III piopOl IIOl
the air resistance dininishes, and conse-
quently the heat of the sun seems to grow
less This explains why the tops of high
mountains are always covered with snow.
Many wonderful discoveries have been
recorded in the Illuminating field of late, and
it is safe to say that this new branch of
science affords one of the greatest fields for
research and invention. Each year our arti-
fetal illuminants are improved; but they are
far from being perfect. Not until the secret
of the FREELY is read, and light is produced
without heat, will our evening lamps be
perfect. Professor Langley and DIR. w. w.
Coblentz have made study of the FREELY;
but have failed to read the riddle. But they
have proved beyond doubt that the light is
not caused by phosphorescence, and that it
has an efficiency of twenty times that of our
best arc lamps.
In the depths Of the ocean, where the sun
light never penetrates and it is pitch black,
there is life and each of these denizens of the
deep carries about with it a small electric
light of efficiency even greater than that of
the freely.