Milford chronicle., 1914-12-04
Really Seen but Once a Year In
the Polar Regions.
A SWING ROUND THE HORIZON.
For One Whole Day, About June p at
the North Pole and About Dec. p at
the South Pole. Old Sol Keeps His
Blazins Face In Full View.

seemingly mysterious natural phenOm
ena which exercise a perpetual charm
over the popular imagination. Tn
northern part Of Scandinavia has &C
quired for itself the distinctive nam
of the Land Of the Midnight sun.
but the title should be extended to in
clude a complete circuit of the eartl
along the arctic circle Then. too, th
southern hemisphere has a precisely
similar phenomenon. which occur
along the antarctic circle. including
portion Of Wilkes Land
Properly speaking. a midnight SUI
is seen but once a year in either hemi
sphere
COnhning our attention TO the north
ern hemisphere the midnight sun il
visible near the arctic circle on tn,
date of the summer solstice. which oc
ours about June p at the time wheI
the sun in It's apparent annual circuit
Of the sky reaches its greatest north
ern decination. which means its great
est distance north of the equator Thi,
distance in angular measure is abou
23l5 degrees. which is precisely equa
to the inclination Of the earth's axis
Of rotation from a perpendicular 10 the
plane of its orbit around the sun.
The arctic circle is situated this sam,
angular distance C23la degreesl from
the north pole When the sun is di
rectly over the equator. about Marct
21. its light reaches simultaneously
both poles Of the earth AS the SUI
begins 10 move northward the lighl
quits the south pole. which then en-
tiers its period Of six months night
But at the same time the sun rises
higher at the north pole which i'm It's
turn enters upon its period Of sil
months day
In the meantime. along the arctic
circle. the days grow longer and the
nights shorter as the sun comes con
tinually nOrthward. until. at the sol
stiee. when the sun is 2315 degrees
north of the equator. there will be one
period of twenty four hours during
which the sun does not set at all in
the arctic circle
At the hour of midnight on that day
the sun. describing a circle through
the sky. just touches the edge Of the
horizon in the north. like the bob OF Il
gigantic pendulum. and then. without
disappearing. Immediately begins to
rise again to describe the other half
of its sweep In the sky
This is the phenomenon called the
midnight sun"
Conversely at the time OF the winter
solstice. which occurs about Dec %
when the sun is at its greatest south
ern decllnatiOn there is one absolutely
sunless day ON the arctic circle. when
the sun skins just under the southern
horizon at noon
A. matter OF fact. owing to the
effects Of the refractiOn of the atmOs
phere. which means the power Of the
air to bend the rays Of light 80 that
the sun appears to Ike above the hOri
zOn by about its own diameter. when
II iS really its own diameter belOw It
the phenomena lust described are Wis
lble half degree HbOut thirty i've
miles, south Of the arctic circle
After the day of the sOlstice the sun
begins To dip below the hurizuu again
because It IL then going south once
more. and the nights beginning With
a length Of only n few minutes. grad
nally increase until they. too. for one
single OccHsi0n. attain the length Of
twenty-f0ur hours
Within the arctic circle the days ana
nights. alternately greatly exceed
twenty four hours in length At the
very pole. as we have seen they each
last six months In I.apmnd they may
be a month long and nj thP North
cape three months Garrett T. Servtss
IN Spokane Spokesman Review