Omaha daily bee., 1916-03-07

propounded often
The earth IL the in winter than IN sum
r,er in the northern hemisphere but In the southern
hemisphere the earth IL farther from the sun In win
/ ter than In The reason Is two-foio Fns''
because the Of the earth in which It travels once
a year around the IL not circle but an eh'pse'
and second because the axis round which the earth
roates once every day Is not upright. but 10 inclined
in nich direction that when the Earth 10 on one sioe
Of the the northern end (Which We WI cali tne
upper end leans toward the sun, ana when II u on
the opposite side the same leans away from the
II IL summer in either hemisphere when that hems
phers leans toward and winter when It leans
away Now The is not situated In the center OF
the eulptloaI earth but In one OF the two
foci which every elpse hes. The focus occupied by
the sun is about 1tcoOoo miles from the center
It so happens that the northern end of the ssrths
axis leans toward the when the earth is In the
part Of elpse which IL farthest from the focus
and away the when the earth IL in the part
Of the ellipse which is nearest Thus summer IN the
northern hemisphere. occurs when the earth Is fathe
from the sun and winter when Il n nearest In the
southern hemisphere exactly the opposite state Of
things exists
In order TO illustrate this for yourself take rubber
ball. ball Of and pass long needle directly
through its center The bail viii represent the EARTH
and the needle the eartts axis Stick end OF tho
needle in flat piece OF wood which can be moved
about the surface OF table and Let the needle loan
position Then set up in the middle OF the table some
object on with the ball. TO represent the
Slide the ball its little platform around tho sun
in elliptcai oval path, whose longest diameter
extends lengthw1se Of the table. Keep the sloping
needle always parallel TO the longer sides Of the table
You will then perceive that the two hsmispheres OF
the earthball north and south and lower).
alternately incline toward the Now place the
little distance away from the center OF the
eIptcsl path but keep it on the line of the longest
diameter Of the ellipse. and you will find that the
winter OF the hemispheres will when the
hall Is at its greatest distance and the winter OF tho
other hemisphere when the ball 10 at its least distance
The difference between the greatest and least dis
tances Of the earth from the sun (which called
respectively apheon and perihelon) Is equal twice
the SUMS distance from the center OF the elpse II
amounts to about 100000 miles, the distance
between the earth and the being 100000 miles.
This makes about per cent difference in the amount
Of heat received by the earth at the two extremes Of
It's orbit
The southern hemisphere has a hotter summer then
the northern. because It's perIhelon;
but 10 compensate this the southern is a
week shorter than the northern since the earth
faster in its orbit when II is nearest the sun. On
the other hand. the southern winter. occurring in
aphelIon, when the earth only slower but
a farther from the sun. Is both longer and colder
than the northern winter.
This is OF the reasons why the accumulation "
everlasting Zee around the South Pole greater than
cept the Antarctic continent do suffer than
the northern from the seventies winter because
Of another compromising circumstance which 10 that
there much greater expanses OF ocean IN the
southern half Of the world and they have the effeor
OF moderating extreme heat and cold
All these things look like very careful adjustment
Of conditions for the benefit the earths inhabitants
but the adjustment only temporary or periodic on
account OF the fact that the direction which tho
earth'G axis points is slowly changing. This change
Ia produced by the procession OF the equinozes which
cause the earth's axis 70 swing round IN space in
such manner that the North Pole. for instance
describes circle In the sky about ~ degrees in d.
ameer, the period Of time required for complets
circuit being about 1900 years
This. combined with the effects OF a gradual change
In the direction OF the longer diameter earths
orbit the Zine OF apsides." will bring about an
entire reversal OF the state Of affairs 1000
years hence, and then the northern hemisphere win
have its winter at apheon and its summer at
pertheiion. The consequences likely to be very
serious because the northen hemisphere has moro
land and less water than the southern ana thus there
will be no compensation for the long. cold winters
and the shortened though hotter. summers. The ci-
mate Of New York may then be severe as that OF
Labrador One cannot the value OF real estate
to hold good for 10000 to come and spectators
In futures should establish relations with the pro-
cesson Of the eauinoxes and the apsides Of the eah
orbit