Idaho semi-weekly world. [volume] (Idaho City, Idaho Territory) 1875-1908, 1890-04-25

dimensions OF Sirius by this means.
Bright as the Dog-star appears to the
NAKED eye, In the telescope it appears az
mere point Of light; and even in tho
largest telescopes constructed. though
LIB iight Is greatly increased. a definite
use or outline, as is seen in the ,lana,.
~ quite undiscernible; for IL the nowo,
OF telescope was sufficient to "raisa y.
disc on the star, 1t would he .lroa.
impossibility to distinguish it. owing tn
its great brilliancy; for as Sir William
nerschel tells us, when Sirius was about
70 enter the field OF view of his for,y.
ieet reflector, 1.-THE light resembied that
which announces the approach OF sun-
rise; and when the star was in tho fe1d
OF view sit appeared in all the snlendor
Vi .he rising sun, 20 that it was inpos-
slble to behold it without pain to the
eye" '''
NOW, II astronomers could measure
the disc Of Sirius, they could from that
determine its distance and measure ;,s
dimensions; but as no outline is annrec;.
apie, they resort to comparing the light
received from this star with that which
we receive from the sun, and by this
means they are able to form some con-
clusion as to its probable size. After
the most careful comparison of the
lght OF Sirius, the sun and other stars.
astronomers agree in fixing the volume
OF Sirius as exceeding our sun nearly
i've thousand times, and his diameter
as exceeding our SUMS seventeen times.
so that the diameter Of this giant orb is
probably no less than over fourteen mil
lions Of miles''
10 the philosophers and scientists of
the last century, it must have appeared
incredible that at any future time scien-
tific discoveries would have enabled us
to tell with certainly the composition of
the stars. Yet during the last fifty
years the science of spectrum ANALYSIS
has SO far advanced, as to give us unde-
niable proof of the existence of certain
elements in the sun and also in the
stars, similar to those with which we are
acquainted on earth As Dr. Higgins
says: ''We now need not teach our chill
dren that little coup,et Twinkle.
twinkle. little star, how ! wonder what
you are" because we really know; we
have in the place of wonder, knowl
edge" OF this method of ascertaining
the composition OF distant body by its
light, it is sufficient here to remark that
it is due to the fact that, when ray OF
light has by means of the spectroscope
passed through glass prism, it is
spread out into broad band comprising
all the colors of the rainbow. This
band or spectrum is in the case of the
sun and other similar bodies crossed by
number of fine dark lines, which cor
respond to the various elements present
in their constitution. Now, if certain
gases. such as hydrogen or sodium, be
burnt and their speetra examined, lines
similar to those in the suns spectrum
will be found; and if the two are com
pared, the presence or absence OF such
elements in the sun may be inferred.
By this means of spectrum analysis it
has been found that the sun contains a
large number of terrestrial elements, in
Guiding hydrogen. iron, sodium, magne-
stun, zinc, lithium. copper, oxygen and
many others; of these, the first four
mentioned have been discovered in
Sirius; and doubtless most of the others
exist also, as the spectrum OF this star
resembles that of our sun in all essen
tial respects, though it can not be OBJ
served under the same favorable con-
ditions.
BY means of the spectroscope a very
wonderful discovery had been made re-
speeding Sirius. Astronomers has no.
ticed that this star was in rapid motion
through space. as it was found that year
by year it was changing its position in
the heavens. traversirg in about fifteen
hundred years space equal to the APP
parent diameter of the moon. alta velocl-
tv of no less than twenty miles per
second. OF course. by actual obsefTa-
ton the only motion capable of being
detected would be that which was square
to the line of sight, so that although
Sirius appears to us to move across the
heavens, he may really be travelling IN
a slanting direction, either towards or
from rs. No one would ever have ex-
nected to be able to tell whether star
was approaching to or receding from US
vet even this seemingly insolYaoie prop
lem has of late years been accomplished
Inv the spectroscope DR.. Higgins, our
greatest authority on this subject, hay-
mo identified certain lines in the spec
trum of Sirius as those OF hydrogen
found on comparison that these were
disnIaced in such manner as TO indl-
cate that the star was recedlng from US
It has been estimated that this recess
sion combined with the thwart motion
Of twenty miles per second, gives as the
actual movement of Sirius in space
speed Of about thirty-three miles per
second.
These. then. constitute some OF the
chief items Of information about SIRIUS
AT present within our knowledge
There seems to be no reason TO DOUBT
that. in common with other suns he mas
his system Of planets circling rouno
him after the manner of our own SUM-
and what a system! Vast as ours ap-
nears. it is dwarfed into inSignlheahce
romDarad with a system whose ru!'hs
orb is five thousand times larger ina"
that which does duty for us l t
seer,s also no reason to doubt that THESE
pIanets are intended to be the aoode OF
life: it may be that al the present nv NO,
mept none OF them present any SlshS u
life; but l think we may safely lu'.. .
without improbability. that each one .. .,
those worlds has a destined period IN ~,
development during which, life similar ,.
TO that which now prevails on our planet;
wnnld be in eXistence. w NV