Omaha daily bee. (Omaha [Neb.]) 187?-1922, 1906-03-25

world. Six months ago engineers believed
the feat impossible.
! New Methods of Lighting.
! Since the introduction Of the bright light
each of our expostions and one of those
abroad has exploited a new method OF
lighting; a fair indication of the way we
have maintained our lead in illumination.
The Centennial exposition was character
lied by the arc light. The Chicago exposi-
ton was lighted with electric incandes-
cents, which replaced the arc for the first
time as an outdoor light. Atlanta produced
| the perfected Welsbach, Nashville the
acetylene light Omaha returned to kero-
sene with the Kitson light, which burned
oil under pressure in a Welsbach mantle
At the Paris exposition appeared the
! Nernst light, an incandescent without q
vacuum, formed by a glowing cylinder OF
magnesia and zirconia. Buffalo introduced
the osmium and Portland the tantalum
| light in which the carbon filament of the
ordinary incandescent is replaced by a wire
of metallic osmium or tantalum. St. Louis
showed no new illuminant, but did bring
forward radium.
Radium itself is not likely ever to be
direct source of light-its illuminant inten-
valuable purpose In the history of illumina-
ton. II made the public for the first time
aware of the two warning principles OF
light, glare and glow. 1t advertised the
idea of illumination by glowing surfaces
instead OF by glarins points.
In illumination .as in other lines OF hui
man activity, there is kind of progress
beside which the contributions OF particu-
lar men are almost childish, tide i'm which
Individual impulses are no more than waves.
This tide radium lifted from the subcon-
seriousness to the consciousness Of the
public 1t revealed the fact that there
had been growing, gradually and without
recognition a demand for light from radi-
ant surfaces instead Of from brilliant
points, a rebellion against the intensity Of
the kerosene flame and the torture OF the
arc light. Radum kindled this rebellion
into open revolt.
Exposition Tests.
The trend of illumination, as well as the
invention of new lights, may best be traced
through the expositions. the business Of
which is to inform the public of the latest
tendencies of civilization. Mention should
be made first however. Of gas, which ante
dated both expositiohs and kerosene, a
smoky, wavering flame such as you can get
holding a match to the open pipe. The jet,
by which two fine currents of gas are
forced together and hattened into a fan,
produced a bright light, as did the chimney,
by bringing greater supply OF oxygen in
contact with a smaller supply OF fuel. But
. though the jet followed the chimney its
light was inferior. The gas sname is more
intense and glaIing than the oil fame, and
, because even pressure in a gas pipe is inn
possible) it is not nearly as steady.
The are lights OF the Centennial were a
further retrogression. Their intensity was
painful; they were all glare and no glow,
They emphasized the darkness around them
instead OF softening Il. And their violet
tinge aroused a constant protest from the
eye. The violet waves are the most perish
able of the constituents OF light. They are
the first to be absorbed by the refractine
medium; even glass absorbs them; so does
air. Sunlight, which developed the human
eye practically without competition until
1850, reaches it shorn of most OF it's violet
rays by the atmosphere-yellowed, so thai
the eye has a constitutional preference fol
yellow and aversion for violet light The
retinal capacity for violet has been weak
ened by disuse so that we really see less
clearly by a violet light than by a yellow
light OF equal power. Moreover, the violet
light Of equal power is actually, so &c
speak. the weaker. for many OF its pre-
ponderant rays are absorbed by glass and
air on their way 10 the eye. while the
yellow reaches the eye intact
Glow and Glare.
The preference Of glow TO glare is sim
larry due TO the structure Of the eye Up L
1850 the only offensive light was the direc
sun. Whatever she may have done for th'
eagle, nature shirked her plain duty OF ad
justing the human eye 70 direct sunlight
she merely protected Il with lid. And
since offensive lights became common, sh'
has taught the eye not TO endure but onl,
to dodge them. The same amount Of light 4
more grateful I'm a broad. evenly distributed
glow than in a single brilliant point. for th'
same reason that heavier weight is easie
70 lift with all the muscles OF arms, bacl
and legs working together than with one
finger Light from one point is focused e
one point I'm the back OF the eye, and th'
strain OF meeting its entire intensity falls
upon a single rod or Gone" Of the retina
The same amount OF light from a broad
surface is distributed over a. wide tract o
the retna, no part of which is Overstrained
The only illuminations worthy OF tie nam
al the Centennial were the fireworks. which
were thought remarkable. Fireworks alas
have lost their charm Our children do no
love them as We loved them I'm childhood
More brilliant than ever. they seem less so