The Washington herald., 1922-03-20
SPRING ARRIVES
TOMORROW MORNING


At t:fs o. m. Eastsrn Standard
Time, tomorrow. spring arrives The
sun crosses the equator going
north The line separating day and
night then passes through the poles
length all over the globe. And
while spring begins in the North
ern hemisphere, fall is insugurlted
in the Southern hemisphere
On this day the sun passes d.
rectly through the zenith at the
equator rising due East and setting
due West After this date ~ rises
in the Northern hemisphere North
\ Of East and sets North Of West
so that II will shine for a part OF
the day on the North sides OF our
houses until IL again reaches the
equator going South in the fall.
At the North Pole the plane OF
the equator comedies With the
horizon plane so on this GATE, or
rather a few days earlier owing
to the effect of refrsction, the sun
appears on the horizon and makes
a complete circuit OF the heavens
in tventy-four hours without set.
| ting. This brings TO an end the
long winter OF sixS months durs-
| tion.
From this time until th, sun
crosses the equator going South in
| September IL remains continually
above the horizon for the observer
at the North Pole and gradually
makes it's way upward until II
reaches an altitude OF % L. de-
grees at the beginning of summer
in June. II then begins TO grad
uzlly wend its way downward once
4 ~.
pezring beneath IL at the beginning
Of fall for another six month";
At latitudes between the North
Pole and the Polar circle the sun
appears above the horizon before
the beginning OF spring and rises
and sets daily until IL reaches
distance North OF the equator equal
| to the observers distance from the
Pole II then makes . complete
circuit OF the heavens without set
ting. touching the horizon at the
north point and the phenomenon OF
the midnight sun can be seen The
sun remains constantly above the
horizon from that day on, attain
ing a little higher altitude each
day until the beginning OF summer.
After that its altitude above the
horizon begins to decrease. When
! il has reached the same point as
before on its southwark journey II
rises and sets daily once more un-
\ til il is as far South OF the eous-
tor as the observer is from the
North Pole when IL disappears com
pIetely from view below the hori-
zon and the long winter night sets
| in to last until the sun has passed
/ through the winter solstice and has
again reached the same distance
South OF the equator on its return
| journey TO the North
At the Polar circle, z3h degrees
| from the pole, tn. midnight sun
is seen on only one day. that OF
the summer solstice. when the sun
is 234 degrees north of the equs
tor Between the Polar circle and
J the equator the sun rises and sets
daily. the difference between the
length OF day and night being most
pronounced In high latitudes.
1 Although. theoretically. day and
| night are equal in length at IN.
beginning Of spring the refrsction
Of the suns rays by the esrth's
atmosphere causes the sun 20 sp-
pear above the eastern horizon be-
fore IL has actually risen and 70
be visible above the western hori-
zpn after IL has set. As a result
the day Is heightened AZ the cN-
pense OF the night by several mir
utes. OF course. at all times Or
Il year the effect of retraction is -
lenEthen the day and shorten the
night by a small amount.
By Isabel N. Lerols, Of the U. S. Noya,
Observatory.