Omaha daily bee. (Omaha [Neb.]) 187?-1922, 1914-08-11

no spectacle in its repertoire more erandlv
beautiful than a thunder storm. but when
the lightning begins to play, terror usu-
ally so dominates the mind OF all behold
ers that they neglect TO notice the mar
vellous details of the great atmospheric
pageant. II is to the credit of "A. Rs"
steadiness of nerve that he has observed
so closely the many delicate hues that
vivid lightning often presents. Most per-
sons, 1 think, are unaware that Light
ming ever Is colored. although IL always
impresses some as being fiery red, prob
ably an effect of the excited magination.
The incandescence If lightning is due
u the intense heating of the gases of the
atmosphere through which the great cleo
trio spark (for lightning is merely such
''spark'D passes.
The molecules of the air are ser into
vibrations sufficiently rapid to produce
light waves in the surrounding ether.
Any solid particles OF dust or haze float
Ing in the air in the track of the discharge
are also heated to the ineandescent point.
The atmosphere UP TO a considerable
height always contains vast numbers of
such particles.
The prevailing hue OF lightning q a
dazzling white. because the heat is 40
great that the entire gamut OF vibrations
that produce the effect OF light il set a.
culver at once, and the primary color
waves Of which that gsmut is made I'm
are all blended together, as they are in
sunlight. But often, as "A. r." has no.
ticed. lightning exhibits decided color
tints. which are sometimes very striking
and beautiful. These are due to differ
In
Of its floating contents, along the path OF
the lightning. as well as TO variations in
the discharge itself
II has been observed that the colors ex.
hibited by lightning are much less varied
ana VIVID In temperate climates than they
are In tropical aud equatorial regions.
Araso though that the yellow, red, blue,
violet and purple unts often exhibited by
lightning depended upon the quantity OF
electricity traversing the air upon the
amount OF moisture contained in Il. and
upon the nature OF the floating vapors
and dust through which the lightning
passed. This. 1t must be said. is a sort
OF scoop-net explanation. and yet. per-
haps. II would not be practicable to give
a more detailed one that would have a
general application. II one knew the pre-
else condition and contents Of the body OF
air through which a lightning flash
passed, It might be possible 20 point out
the exact origin Of the colors shown, but
a great lightning flash is sometimes sew
eral miles In length, and evidently no very
accurate idea OF the state OF the air
throughout so large a space could readily
be obtained.
The same flash might exhibit varying
colors at different points along its
course.
The explanation which Arago suggested
for violet colored lightning was that it
probably occurred at a great height above
the earth. where the relatively low den
sity OF the air would produce conditions
somewhat resembling those in a partially
EXHAUSTED, OF Geisser. tube. through
which electric discharges are passed. AS
is we'll known such discharges exhibit
violent tints. In connection with this IL
may be mentioned that thunder clouds