The Marion daily mirror. (Marion, Ohio) 1892-1912, 1909-09-15
THE EARTH'SM MOTIONS
How We Are WhirIing Around
and Through Space.
THE INFLUENCE or THE SUN.
Without Its Attraction That Draws tho
World Toward II In an EIIipticaI
Course Our Globe Would Wander on
Forever In a Straight Line.

moving from one point to another of |
the earth-trovel they call it--and yet |
pay little heed TO the wonderful Jour. |
pey Of the earth itself. Many. again,
go to seek a climate while the hurry. |
Ing earth Is bringing TO them one ell. |
mate after another In endless success
sion. Those who have not hitherto
taken much notice of the earth's prog
ress-wbo have not, so to speak, looked
out Of their carriage window as they
are whirled along-might find new
interest In doing so. Look, for exam
pie. at the apparent size of the sun.
Casual observation shows that It ap.
pears larger In the winter heavens.
And exact measurements tell us that
1t Is largest on Jan. / and smallest on
July 2. The size OF the sun thus marks
the earth's nearest approach and
! greatest distance from the sun. Accu-
rate astronomical measurement of the
suns diameter might even determine
the day Of the year. for the daily varl-
alton In the apparent size of the sun is
some nine-fiftieths of second of an
| guar measurement. And astronomers
profess to measure the second decimal
| of seconds.
| There are three ways In which we
are journeying with the earth. There
is, first. the daily revolution, which car.
| rles us through, n complete circle In
| twenty-four hours at n rate varying
| from rather more than thousand
miles an hour at the equator to moth
| N nj hn M hr
way, has over been. Then we are trav-
cling around the sun once a year at
the rate of eighteen miles second
Thirdly. we are journeying through
stellar space. for one OF the most re-
markable facts which modern astron-
omy has brought TO light is that our
solar system, the sun with all its plan
cts, Is on journey toward the con-
stellatlon Lyra at the rate of ten miles
a second.
AS we sit in train and are whirled
along It sometimes appears as If the
scenery were flying past us rather
than we past Il. SO the daily revolu-
tion of the carth-a thousand miles an
hour at the equa tor-makes the sun
rise and set. and our yearly journey
makes the sun apparently travel
through the consultations of the 20
diac. If we move round any stationary
object on the earth we see It with n
constantly changing backgronnd-now
a windmill. now a cottage. now a
wood. now n church, etc. So MS we
travel round the sun we see 1t with an
ever changing background of stars
now those of Aries. now of Taurus.
now of Geminl, and so on. The posi-
tlon Of the sun among the stars marks
the stages of the earth's annual jour.
ney. And as the earth arrives at diff
ferent points of It's orbit the times Of
the rlslngs of certain stars vary. These
indications OF the earths progress
have been taken as marks of the sea-
sons. Thus when Sirius rose with the
sun 1t was known that the dog days
had begun. Early astronomers watch
ed carefully for the rising of the dog
star. The Egyptian astronomers look
ed for the heical rising of Sothis to
proclaim the new year.
IL is the earth's yearly journey round
the sun which enables us to determine
the distances of the stars. The method
is precisely that adopted by surveyors
for determining the position of objects
on earth The direction of the object
| whose distance is 10 be found is OBJ
served from two points a known dis.
tance apart. The rest is mere calcula-
tion. In the case of the stars the direc-
tions are observed from two extreme
points In the earths orbit instead Of
from the two ends of base line. The
process is called triangulation when
applied to earth measurements. and
everybody understands what 1t means,
When applied to the stars 1t Is called
parallax and remains mystery TO
most people. Such is the obscuring
power of a word.
The "little more" and the "little less"
OF Browning are forcibly illustrated In
the direction Of the earth's journey
round the sun. An elliptic course diff
ferlng very little from circle, COM
bned with tilt Of the axis. gives us
the seasons. But IL this difference and
| tilt did not exist there would be no
seasons and one climate would rule
the year. III, again, the course were
more elliptic, then for the hemisphere
whose winter occurred at the earth's
greatest distance from the sun there
might be n glacial period.
"The straight line" says Miss Helen
Keller. "symbolizes duty. II is a dun
thought drawn ont endlessly" And
this seems TO be reflection on what
we had though. was the earth's path
Of duty round the sun, for this path is
the curve known as the elllpse. More
over, the thought makes the sun a
tempter OF the earth from tho strict
path OF duty. for the earth. we learn
from our Newton. II left to Itself
would wander on forever through
space In a straight line. II is the sun
which draws II from this dull course
into the pleasant curve Of subsection
Yet the suns victory is only partial
the earth's actual path being combi
nation OF its own straight line OF In,
clinnton and obedience to the pull OF
the sun And so instead of the 'dul'
thought drawn out endlessly" we have
the beautiful thought of the changing
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