Jeffersonian Republican. [volume] (Stroudsburg, Pa.) 1840-1853, 1850-11-28

small p0x internally .-HdrJ0rt Chr0nicle'
The Duration of the Earth,
AS INTIMATED BY ASTRONOMY.
THE following views, by a correspondent of the
Puritan Recorder, upon the, Duration OF the
Earth" as indicated by Astronomy, will be read,
we think, with much interest.l
The evidence which geology affords of the great
intiquity of the earth. turns thought TO the evil
dence which astronomy furnishes of its future con-
tnuance. From the many striking resemblances
between the bodies that compose the solar system,
we infer for them common origin and common
destiny. The earth then, will probably live while
the system lives, and no longer What its partic-
ular destiny may be, and by what means brought
about. we stop not here to inquire. Our only pur-
pose now, is TO consider some intimations furnish
ed US by the system ITSELF that it is fashioned for
long duration. This is indicated by the i'm
mense length of some of the periods involved in
this system.
According to the commonly received chronolo-
gy, the planet Neptune has had but thirty-six Of
his years since the creation OF our race. If the
analogy between the earth and that planet holds
good, then the first generation of his nhabitant is
hardly yet passed away. Some comets have not
yet had one year since the date of Adams crea-
ton.
But there ale periods of greater length still =
The earth's Perihelion IS slowly creeping around
the orbit from West to East, at rate which will
require III 900 years to complete the circuit
The Periheion OF Murcury is moving in similar
manner, at rate which will require 100000 years
to complete it. Other planets exhibit the same
movement. Now if all the planets in the system
were arranged along in a line on the same side Of
the sun, and all in their Perihelia, e., all in that
point Of their orbits which is nearest the sun, and
then all their orbits set revolving according their
present laws of motion: millions of years must e.
lore oil of thnpo he
same circumstances to hold their family festival
preparatory to another revolution of the same
length. rr -r
The earths' orbit is now an ellipse, but is slow
ly becoming circular and its present rate OF
change, will become perfect circle in about half
million of years from this time. Thenit will be.
Gin to resume its eptcal form, becoming more
and more eliptical for some millions of years,
when having attained the maximum Of elipticity,
it will begin again to shape itself into a circle
Corresponding with this change and caused by it.,
is change of the period of the moons revolution.
Its period is now slowly shortnng; its motion in
revolution, of course increasing and this rate Of
increase Is such as will make il gain little more
than its diameter in a thousand years. This short
ening of her period and increase of velocity will
continue until the earth's orbit becomes perfect
circle and then she will slowly reverse her move
ments and gradually return to her former cond-
ton.
From the mutual attraction of Jupiter and Sa-
turn, their orbits are passing through similar
changes, the orbit OF one becoming more and more
eliptical while, from the same cause, that of the
other becomes more and more cifcular, in conse-
quence of which motions, the period Of one is
engthening, while that of the other is shortening
This oscillation requires more than 20, 900 years
for its completion.
The sun has what is called proper notion"
l. e., the sum- with all his dependent household, is
sweeping thro' space at the rate of 422, 900 miles
per day. or nearly half its own diameter 1t is
supposed by some good astronomers that all the
stars have similar movement all revolving to-
gether in the plane Of the milky way, about some
common centre; that the orbit described by our
sun in this grand march is so large, that this in
conceivably rapid motion continued for years,
forms practically straight line; in other words,
the orbit is SO large that the arc Of it decribed
since this motion was first observed, is SO short in
comparison with the whole orbit, as to seem to be
no arc at all. At least, no instruments are, yet
accurate enough to detect and measure Its rate Of
deviation from a straight line. Herschell init
mates that the elements Of this orbit may perhaps
be determined after 80 or 40 years observations
with the incest instruments. OF course, many
millions OIL years must pass, ere this asst circuit
can be fully described by the sum- a. ysZ.e = a
We grant there is some little of conjecture at :
tachlng to this last illustration which belongs not
W any VI TIC previous ones; ano vel IL IS muCn IN
keeping with those demonstrated facts, that il can
hardly be call improbable. 4aa ,ti"P1 a9ai9'
Although these periods are ncenceivably long,
still they are none The less periods. They are as
truly periods as fthey were completed in one day
or one hour. The fact that our life is short in
comparison aud that we cannot in our best estate,
have any adequate conception of them, is no more
of an objection to their existence than it. is an OBJ
lection to the length of Nep,unes period that in
sects die after few hours existence, and without
any adequate conception Of an hundred and sixty
four years existence. 9a d|4}stiEaA slA .'ea
From the movements Of the heavenly bodies
through certain part of their orbits of their os
citations, science determines with the greatest
actness the fact that, after a certain point in. de-
Parture is gained, the body will infaliby return 10
its former condition and place. On its faithfully
returning and thus neutralizing the perturbations
caused by its departure, the harmony and stabili-
~ of the whole system depend. e fs'i So 'a'a
Now mark The conclusion. For the same good1
reason that we say the earlh could not have been
made and set rotating merely 10 cause fifty or al
hundred days or wss cot SET revolving around the
Sun to cause only one Or two years, or perhaps