Western liberal. (Lordsburg, N.M.) 1887-1919, 1917-01-05
MIDNIGHT sun
Really Seen but Once a Year In
the Polar Regions.
A SWING ROUND THE HORIZON.

For One Whole Day, About june Fl al
the North Pole and About Dec. % al
the South Pole, Old Sol Keeps His
Blazing Face In Full View.
''The midnight sun is one Of those
seemingly mysterious natural phpnom.
ena which exercise a perpetual charm
over the popular imagination The
northern part Of Scandinavia has &c
Quired for itself the distinctive name
OF the Land Of the Midnight Sun.
but the title should he extended TO In
clude a complete circuit OF the earth
along the arctic circle. Then. too. the
southern hemisphere has a precisely
similar phenomenon. which occurs
along the antarctic circle. including n
portion Of Wilkes Land.
Properly speaking. a midnight sun
is seer but once n year in either hemi
sphere.
Combining our attention to the north.
ern hemisphere. the midnight sun liz
visible near the arctic circle on the
date OF the summer solstice. which &C.
ours about June p at the time when
the sun IN its apparent annual circuit
of the sky reaches its greatest north
ern %declination. which means its great
est distance north of the equator. This
distance in angular measure is about
1914 degrees. which Is precisely equal
to the inclination Of the earth's axis
Of rotation from a perpendicular TO the
plane Of its orbit around the sun
The arctic circle is situated this same
angular distance (23h degrees, from
the north pole. When the sun is di
rectly over the equator. about March
81, its light reaches simultaneously
both poles of the earth. AS the sun
begins to move northward the light
quits the south pole. which then en-
ters its period Of six months night.
But at the same time the sun rises
higher at the north pole. which In its
turn enters upon its period of six
months day.
In the meantime. along the arctic
circle, the days grow longer and the
nights shorter, as the sun comes con-
t~inually nOrthward. until, at the SOL
oAAN(t WhGh tue PUN ID @OT2 u&BAEGS
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 a
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 ~declinatlon, there is one absolutely
sunless day on the arctic circle, when
the sun skins just under the southern
horizon at noon.
AS 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 so that
the sun appears to be above the hori-
zOn by about its own diameter. when
1t is really Its own diameter below 1t.
the phenomena just described are Wis.
Ible half a degree mbout thirty-dve
miles, south Of the arctic circle.
After the day Of the solstice the sun
begins to dip below the horizon again.
because 1t Ia then going south once
more. and the nights, beginning with
a length OF only a few minutes. grad
ually increase until they. too, for one
single occasion, attain the length Of
tw~enty-four hours.
Within the arctic circle the days and
nights, alternately. greatly exceed
twenty-four hours in length. At the
very pole, as we have seen. they each
last six months. In Lapland they may
be a month long and at the North
cape three months. Garrett p. Serviss
in Spokane Spokesman Review.