New-York tribune., 1896-03-29

,sr., hs,vee, thu earliest and latest record II was
computed that the orbit described oy e''her ooa'
was about three times as long as II was "'ue'
When however. an attempt was made 70 ara" d."
exact diagram OF this orbit the observed posi'io"s
would fall into line. There was more OF i iess
rregularity or discrepancy. whatever scheme was
adopted.
Thirty or forty years ago. therefore. suspicious
were entertained By Sir John liersehe, that there
another factor In the a Madras asToh-
omer. jacob went so far az to conjecture that the
smaller revolving around some hitherto
unknown body, like the moon around me eaIth,
(only al a far greater dlstance). and that the two
then revolved around the larger visible star as tne
earth and moon together go around the sun sun, nu'
50 keen,eyed observer as s. , W; burHhamh p, ram,
then with the great Lick telescope. e3ud not ssI
Among those who tackled this fascinating prop,
mithematcian. now c9nnected with ne ss,rohoII-
cal department. OF the Chicago University. hIs
other ASTRONOMERS have enabled him to perceive
NOT on.y that there have been dcv!ations from the
bur- two but also that tro deviation had been sys-
tematc 1t exhibits a .ort or oscuIaton, fron
estimate the position and movement OF the dis
turbing agent.
EVIDENCE OF AN UNSEEN NEIGHBOR
In making such a computation. this fact must
be kept In mind: When large satellite revolves
around a primary the centre OF It's orbit Is not
the centre OF the larger body but point some
where between the centres OF the two masses
near the bigger The primary, too revo,ves
around this imaginary pivot. but. or course de-
scribes a smaller circle than the satellite lhe
relative size OF the two orbits depends on the
relative weights Of the bodies. Hence one can as
certain the mass OF the satellite even II he cannot
see H. by observing how far away from the centre
OF gravity OF the pair (the imaginary piVoO the
primary is. IL Is feasible likewise 10 lfd out now
long IL takes the satellite to make It's circuit, by
watching the wobbling Of the primary Dr. Sees
calculations satisfy him that Jacob was riSht IN
associatng the suspected dark body more directly
with the smaller orb In the visible pair. but he DIFF
o.. I.N oh I'm
makes the dark star the smallest OF the three
and makes II a satellite OF the sina.Ier orgnt '-
years In computing the movement OF these two
with reference 10 tho larger bright star. one must
adopt as the basis OF his calculation that invisible
pivot Of the pair the centre OF gravity about
which the minor revolution Is performed. One
must not be guided by the bright secondary alone:
Making this allowance Dr. See finds tho period
Of the greater revolution to be eighty-eight years.
instead Of ninety-three.
Using 70 Ophluchl as a text, Miss Clerke says
THE discovery OF dark stars solely through their
gravta tional effects must be regarded as signal
knows which to admire most. the compile tted
structure OF the stellar system thus exhibited or
the exquisite workings OF the human Intellect when
these mathematical tasks reveal And as there are
many more buari.s which destroy irregularity.
II Is probable that the field OF research here IN
dlcated is a large one.
In space Is afforded by the sudden appearance OF
certain temporary stars giving peculiar double
spectrum. Each OF these Is now believed TO be
due to A collision between a swarm OF nete0rs
presumption is that every dark star is body
which was intensely brilliant Ike our sun.
owing to Its heat but has radated enough OF the
cold and hard all the way through. or only a cool
shcll over n molten mass. But the history Of such
bodies Is. after all. merely matter OF conjecture