The Bennington evening banner. (Bennington, Vt.) 19??-1961, 1912-10-04
WAVES OF LIGHT.
They Vary In Length and on That
Account Vary In Color.
OUR SUNLIGHT IS PURE WHITE
The Arc Light Is Its Closest Rival,
With Its 10000 Candle Power Per
lnch-The Way Human Being With
X Ray Eyes Would Be Handicapped.

inoh-The Way a Human Being With
X Ray Eyes Would Be Handicapped.
| Light travels at a speed of 10000
miles second. The source of all light,
except the light from fre4lies and their
kin, is a substance raised to tempera
ture sufficient to set up waves in the
surrounding ether Light waves vary
in length between 1-33400 and 1-65000
of an inch, the first being extreme red
and the second being extreme violet.
Rays of white light have a length Of
1-45000 Of an inch. The sun is great
mass of white hot matter.
In an are lamp it is the white hot
particles of carbon floating between
the two electrodes which produce light.
In the incandescent lamp it is the hair
pin filament 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 briliancy of
| about FIVE candlepower per square
inch Of surface The ordinary candle
( flame gives from two to three 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 ilament
incandescents give about 1000 candle
power.
The prism shows us that white light
is composed of n happy blend of all
the colors of the spectrum. The sun
gives the only pure white light, with
the arc lamp a close second, and the
metal fiament incandescents taking
third place Sky light, such as comes
from the north on clear day. is blush
I white Gas mantles give a 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 off only waves
of length 20 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 \ thing looks black when it 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 I'm 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 ewes have only a certain range.
weak enough at hest As we all know.
there ARE times when all appears black
10 Ms and yet animals can see. The
trouble IS the faint light rays move
too slowly 10 be registered on the hui
man retlna The ray has proved he
yond a doubt that there are light rays
which move too fast for human eyes
10 register This light penetrates books,
wood, paper and even human flesh
w TN lut y rays 10 dNNiNt our tAfN
we can see the bones in our arm with
out bothering to remove our shirt But
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 at all. To MS all Is
darkness beyond what our eyes will
register.
Light rays themselves are invisible.
When they move through the ether
alone our ewes 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 retlna, and, behold.
we can see AS the atmosphere thins
rapidly as we go upward. SO, in pro
portion. the air resistance diminishes,
and consequently the heat OF the sun
seems 10 grow less. This explains why
the tops of very high mountains are al
ways covered with snow.-New York
Press.