The daily Alaskan., 1914-11-20
THE MIDNIGHT SUN
Really Seen but Once g Year in
 the Polar Regions.
IA SWING ROUND THE HORIZON.

For One Whole Day, About June 21 at
 the North Pole and About Dec. 22 at
 tho South Pole, Old Sol Keeps His
 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 Sun, 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 a precisely similar phenomenon, which occurs along the antarctic circle, including a portion of Wilkes Land.
 Properly speaking, midnight sun Is seen but once year in either hemi- sphere.
 Confning our attention to the north ern hemisphere, the midnight sun is visible near the arctic circle on the date of the summer solstice, which oc- CUTS about June 21 at the time when the sun in it's apparent annual circuit of the sky reaches it's greatest north ern declination, which means it's great est distance north of the equator. This 1 distance in angular measure is about 231a degrees, which is precisely equal to the inclination of the earth's axis of rotation from q perpendicular to the plane of its orbit around the sun.
 The arctic circle Is situated this same angular distance (23R degrees) from the north pole. When the sun is di- rectly over the equator. about March 21, 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 it's period of six months night. But at the same time the sun rises higher at the north pole, which in its turn enters upon it's 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- tinuaIly nOrthwaru, until, at the sol stice, when the sun Is 231a degrees north of the equator, there will be one period of twentyfour 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 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. p, 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.
 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 tue hort- zon by about it's own diameter, when it is really its own diameter below it, the phenomena just described are wis ible half a degree (abOut thirty-hYe miles, south of the arctic circle.
 After the day of the Solstce the sun begins to dip below the horizon again, because it is then going south once more, and the nights, beginning with length of only a few minutes, grad ually increase until they, too, for one single occasion. attain the length or twenty-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 SpoEesman-Review.