The Democratic banner. (Mt. Vernon, Ohio) 1898-192?, 1912-09-17
WAVES OF LIGHT.
They Vary In Length and on That
Account Vary In Color.
OUR SUNLIGHT is PURE WHITE
The Arc Light is It's clossst Rival,
With lts 10000 Candle Power Per
inoh-Ths'Way a Human Being With
X Ray Eyer Would Be Handicapped.

X Ray Eyer Would Be Handicapped.
Light travels ut speed Of $4,000
miles n sec0ild The source of all light,
except the light from tireHies and their
kin. is substance raised to tempefa.
ture sufficient to set up waves In the
surrounding ether. Light waves vary
in length between l-334O0 and l-65O0O
Of an inch. the first being extreme red
and the second being extreme violet.
Rays Of white light have Il length Of
i-45O00 Of an inch. The sun is u great
mass of white hot matter.
In an arc lamp 1t is the white hot
particles OF carbon floating between
the two electrodes which produce light.
In the incandescent lamp 1t IL the hair
pin tlament inside the glass globe
which. when heated by electricity.
gives off light waves. In gas and oil
lamps light Is produced by the heated
particles Of carbon In the flame above
| the wick or mantle. The eye can
stand without firing brilliancy Of
about ive candlepOwer per square
inch Of surface. The ordinary candle
power per square inch. while the sun
at zenith gives 100000 candlepower per
square inch The arc light ranks next
to sunlight. with 10000 candlepower
per inch and the best tungsten filament
incandescents give about 1000 candle
power
The prism shows us that white light
is composed OF happy blend of all
the colors Of the spectrum. The sun
gives the only pure white light. with
the arc lamp close second. and the
metal filnment incandescents taking
third place Sky light, such as comes
from the north on n clear day. is blush
white Gas' mantles give greenish
light. open flame yellow light and
kerosene an orange light.
In the dark no color exists. The
color of light depends upon the length
Of the waves. The light source which
we know as red gives or only waves
of a length to produce that particular
color A body appears red because Its
surface absOrbs all the other waves and
reflects the red waves back into the
eye A thing looks black when 1t is
capable Of absorbing all the colors at
once.
Light rays. being In active motion.
produce heat when they meet with re-
sistance In their path. This Is why
black clothing Is warmer In summer
than white clothing. the resistance be.
Ing on the surface Of the white cloth.
Ing and nearer the skin when we wear
black.
The eyes have only certain range.
there are times when all appears black
to us and vet animals can see. The
trouble Is he faint light rays move
too slowly to be registered on the hu.
man retlna. The X ray has proved be-
yond n 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 rays to assist our eyes
we can see the bones In our arm with.
out bothering to remove our shirt. But
n man with y 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 mt all To us all is
darkness beyond what our eyes will
register.
Light rays themselves are Invisible.
When they move through the ether
alone our eyes cannot see them; con.
sequently all is total darkness But
when they meet with the resistance OF
our atmosphere. producing heat. they
register on the retina. and, behold
we can see. As the atmosphere thins
rapidly as we go upward. 80. In pro
portion. the air resistance diminishes
and consequently the heat OF the sun
seems to grow less. This explains why
the tops of very high mountains are al.
ways covered with snow.-New York
Press.
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