American citizen. [volume] (Canton, Miss.) 1864-1890, 1874-10-10

particular by Bradley, who, while al
tempting tO. measure the distances O
! the stars by comparing together obseI
, vations made at an interval of 81
months, scovered-something else
Instead of finding the distance of tn
stars on which his observations were d
: rected, he discovered a very importan
optical phenomenon, viz, the abeir0tiO
Of light, the effect produced by the me
ton OF light and the motion of tn
earth combined. Similarly, William
Herschel, while seeking the parallaxe
of the stars by comparing bright star
with their nearest neighbors, discovere,
the systems of double stars. So, toe
Fraunhofer, while seeking the limits o
the colors in the solar spectrum, dis
covered the absorption rays, the study o
which has given rise to spectrum analy
sis. The history of the science show
that frequently discoveries have beef
made in the course of investigation whicl
had but little to do with them directly
Columbus discovered the New Worl,
| while aiming to reach the eastern cOaS
of Asia by sailing to the west. III,
would never have discovered it, woul,
never have sought for it, had he known
the true distance between Portugal ant
| kamtchatka.
1t was not until 1910 that the distanc,
discovery is therefore of recent date, ant
we are only now beginning to form al
approximate idea of the real distance:
which separate us from the stars. Tn,
| parallaX of the star siXty-one in tho
| Swan, which was the first to be deter
mined, was ascertained by Bessel, and
| was the result of observations made al
konigsbcrg from 1887 to 1910. In 1S1:
| AragO and Matthew had made observa-
tons on this star, but without reaching
any certain results. The parallax OF
| Alpha in the Tyre was found by Strive
in the course of observations made at
Dorpat between 1885 and 1888; but it
was not published till after the year 1910
The same is to be said of Alpha in Cen
| taur, observed in 1882 and 1899 on the
Cape of Good Hope by Henderson and
Maclear; this is the nearest to us of all
the stars.
There are two ways of determining
these parallaxes. The first is, TO com
pare together the positions observed at
intervals of six months; the other, to
discover an apparent motion in a star (as
compared with IA motionless star situated
at a far greater distance than that which
is studied; this apparent motion being
due to the perspective produced by the
annual revolution of the earth in its or
bit. This is the method mostly employed
now. Calico, in his g Dialogues; Greg
DRY, in his Proceedings of the Royal
Society" $3.50; Huyghens, in his Cos
motheoros," published in 1885; Condor
Get, in his "Eloge of Roemer," in 1918,
and William Herschel, in 1871, have de-
scribed both methods. Hooke, Flam-
stead, Cassini, Bradley, Robert Long,
Herschel, Piazzi, and Brinkley strove,
from 1914 to 1920 to determine the small
quantity of the apparent movement of
the brightest stars, which used to be
garded as the nearest; but their efforts
were fruitless, owing TO the incOnsiderable
amount of this motion. There was need
of instruments of the utmost precision,
a rigid spirit of observation, and an in
dOmitable patience in order to get at
results.
Since 1910 the attention of astrono-
mers has been oftentimcs directed to this
and thousands of calcula-
tons have been made. With great diff
Guilty astronomers have succeeded in de-
termining the parallaXes of n feto stars.
But the inevitable errors of observation
often involve the results in Obscurity.
Let the reader only bear in mind that
there is not one star that is sufficiently
near to give us paralleX of one second!
A second is the dimension to which
would be reduced circle one meter g
to distance of 206 kilometers Q27.72
miles, from the eye. This appears to be
less than nothing; it is equal to the thick
ness of IA hair stretched at the distance
from the eye of 20 meters GA feet. The
apparent annual movement of star
whose distance can be known is per-
formed altogether within this infinitesi-
NAL space. For an observer on the star
that is nearest to US, this hair would con-
ceal the whole space between the earth
and the sun.
As no star offers paralleX of one sec
ond, it follows that the nearest of the
stars is distant from the earth no less
than 2O6 ,265 times 90 600, 900 miles. The
space which surrounds the planetary sys
tenn is void of stars to that distance at
east.
The star which is nearest to us, Alpha |
If Centaur, has Il parallex of 81 sec. Its |
distance from the earth is 226 100 times |
he radius of the earth's orbit or 81 ,OOO, |
700, OOO, 900 miles This is our HeighJor |
star, and its distance is probably the min !
mum distance between star and star
Il 600, 900, OO0, 900 miles. Each of these
stars shines with it's own lights n sun
ike our own.
The second star in the order of dis
ances is 81 Cygni. Its parallex is 81
sec, and its remotencss 81, 0OO, 0O0, 900 900 |
niles.
OF the thousands of stars which have
Jeen studied, we know the distances of
only twenty. Among these we may sig
laliZe Sirius, sun 2,6SS times larger
han our own, surrounded by a system of
heavenly bodies, several of which are al
'eady known, and distant from us 80 ,OOO,-
)OO,O00,O0O miles; the Polar Star, which
s a double star, distant 292, DOC, 100000
400 miles; and Capella, distant 425,OOO,-
)OO,OO0,OOO-a space which is travcrsed
~ light in seventy-one years and eight
months; SO that the luminous ray which
must have started out in 1903. Capella
night have been eXtinguished in 1904,
tut we should see it still. 1t might 90
tut to-day, and yet the inhabitants of
he earth would continue to admire it in
heir heavens until 1916. Conversely, if
here existed, on the planets gravitating
ound Capella, minds whose transcend
mt vision could thence descry our little
arth, lost as it is amid the suns rays,
hey would now see the earth of the year
SOB, and would be seventy-one years
light months behindhand in its history.
'hese are the stars that are nearest to us.
The others are incomparably more re-
note There are stars whose light can
ot reach us in less than 100, 1000 or
1000 years, though light travels at the
ate of $4,000 miles per second! To
raverse the sidereal world of which we
Drm part 0he Milky Way, light takes
1000 years. To reach us from certain
+ the nebul;e it must travel for three
undred times that period, or 5,OOo,Ooo
ears. Let the Imagination, that is not
onceive of them. If it does not expert
mo- no tip, nf Ia in "a, lp |