The Hartford herald. [volume] (Hartford, Ky.) 1875-1926, 1915-10-06
THE MIDNIGHT sun
Really Seen but Once a Year In
the Polar Regions.
A SWING ROUND THE. HORIZON.
For One Whole Day, About June Fl at
the North Pole and About Dec. 22 at
the South Pole, Old Sol Keeps His
Blazing Face In Full View.

Blazing Face In Full View.
"The midnight sun is one of those
seemingly mysterious natural phenom-
ena which exercise perpetual charm
over the popular imagination. The
northern part of Scandinavia has ac-
quired for itself the distinctive name
of the Land of the Midnight Sum-"
but the title should be extended to in
clude a complete circuit Of the earth
along the arctic circle. Then, too, the
southern hemisphere has precisely
similar phenomenon. which occurs
along the antarctic circle. including a
portion of Wilkes Land.
Properly speaking, a midnight sun
is seen but once u year in either hemi-
sphere.
Combining our attention to the north
ern hemisphere, the midnight sun is
visible near the arctic circle on the
date of the summer solstice, which &C.
ours about June 81 at the time when
the sun I'm its apparent annual circuit
Of the sky reaches its greatest north
Gil htNiihdNlOiis ihNdho It's SAtat
est distance north of the equator. This
distance in angular measure is about
23ta degrees. which is precisely equal
to the inclination of the earth's axis
Of rotation from n perpendicular to the
plane of its orbit around the sun.
The arctic circle is situated this same
angular distance (231a 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-
tiers 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-
tinually northward, until, at the sol
stice, when the sun Is 23h 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 a
gigantic pendulum, and then, without
disappearing, Immediately begins 10
rise again to describe the other half
OF its sweep in the sky.
This is the phenomenon called the
midnight SUM-"
Conversely at the time of the winter
solstice. which occurs about Dec. %,
when the sun is at its greatest south.
ern declination, 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
afr to bend the rays OF light so that
the sun appears 10 be above the hori.
zon by about its own diameter, when
II is really its own diameter below II,
the phenomena just described are Wis
lble half degree about thirty-fiye
niles south Of the arctic circle.
After the day of the s0lstlce the sun
begins 20 din below the horizon again.