The enterprise. [volume] (Wellington, Ohio) 188?-1899, 1890-08-06
Why rns SKY is BLUE.
a vs-iety os Prominent Heavenly Tints
CIeveriy Analysed. n y. !. q.

a vs-iety of Prominent Heavenly Tints
g CIeverIy Analysed. 4
"Yon havc all noticed" said an as
tronomer TO a Cincinnati Times-Star
man "that When we look away from the
ann into the cloudless sky. the heavens
annear blue, when, however. we look Ia
the direction Of the sun. especially
when. after sunset, we look toward the
uastern horizon. the color Is q yellow
lsh red. With the spectroscope It can
be shown that the white light from the
suh Is produced By mingling OF differ
ept colored rays, Indeed this can be
aSown by means OF any triangular
nrism, saw one OF the pendants OF a
chandelier. One Of these placed in the
nafh Of a beam of light will project on
screen a. band OF seven colors-red,
oranrc. yellow, green, light blue, dark
hlue and violet. Understanding this,
wScan readily see how the effect Is blue
when piece OF blue glass Is interposed,
or.red when red glass is used. All but
tlie blue and red rays respectively are
absorbed; these, however, pass through
freely, and we say that the body Is
blue, or red, when really the color
Is not property OF the glass in any true
sense, but OF the sunlight What has
this to do with the sky colors? ! will
now show you. Dissolve little white
castillo soap in tumbler OF water, so as
to mako the water slightly turbid. Place
ablack screen behind the tumbler and
hold tho whole so that the sunlight
must be reflected from the liquid before
1t can reach your eye. The liquid VIII
appear blue. Hold 1t next In q direci
line toward the sun and 1t appears yell
lowish red Now these are the exactap-
pearances OF the sky Sky light Is re-
fracted light The water particles In
the atmosphere, like the particles OF
soap In the water. retract blue lighti
while tho background OF darkness sur
rounding the earth replaced the black
screen. The atmosphere, like the solu'
tion Of soap and water, transmits yel
low and red rays but slightly refracteo'
while tho olue' being o weak coior' ~
refracted too low TO 90 Scent hence wnen
We look toward the source OF iishtm
the evening or morning the SKY Is OF
yellowish rcd cclor ihis onect IS more
pronounced then than during the oay'
because when the sun is near the horf
zon'the rays travel greater distance IN
the air In order 10 reach the earth than
when directly above u.s. consequently
the bluo rays are more thoroughly
refracted.
Tho atmosphere has many effects In
modifying the appearance OF tho sky
: and the heavenly bodies. Look at Venus
over there near the western horizon ana
Just below the crescent moon, which has
come into plain view while we have
been talking Ton account OF the deepen
ing darkness) Its real distance from
the horizon Is not as great as It appears
for tho rays OF light which trenects TO
us, and which IL receives from the sun,
are bent downward when they pass into
our afr, perhaps fifty miles from the
earth's surface. - 6saHares Bae,
"As tho effect Is the same as that
which would be produced were there nc
atmosphere, by rays proceeding from a
higher star, we locate the body In a
more elevated position than the one
which Il actually occupies Put dime
on the bottom Of q pail hlled With water
and uhave like conditions With simi.
lar effect IL you place your hand
where you think you see the com you
will not touch IL but spot perhaps an
inch above the true bottom. Again, &c
you notice how steadily venus shinesT
II you arc here In an hour later, when
the stars are all out, you VIII observe
that all those near tho horizon,
the others to a smaller extent
are merrily twinkling This ap
pearance, made familiar 70 all OF us By
neutrality-suspicious.; Twinkle, twinkle
littlo STAR is not noticeable In the
case OF any planet except Mercury and
has beon q subject OF much study on thu
ally believed that IL arises from the un