Public ledger. [volume] (Memphis, Tenn.) 1865-1893, 1869-05-13

Return of a Comet.

The London Daily Ne'os, OF April Il
says:
During the last few weeks astronomers
have been on the look out for the return
of one of those periodical comets which
form, so to speak, part of the solar fam
lily. The brilliant comets which come to
US from out the depths Of space, and, af.
ter blazing in our skies for greater OF
less interval, pass away again into those
same unfathomed abysses, are, by com
| parison, mere occasional visitors. But
! there is set Of small comets which regu-
larry, and ct short intervals, return to our
| neighborhood and the one we are now
dealing with belongs to this class. News
has just come from foreign observatory
that the wanderer has been discovered.
He is now traversing the inconspicuous
constellation ofthe Hunting Dogs; but il
is as yet far too faint to be seen without
powerful telescope Even the posses
sor Of such telescope would find it diff
cult to discover the comet were not its
place accurately indicated, since in the
neighborhood of its path the mysterious
nebu'@ are spread with unusual profu
sion. On this account it may be we'll fol
those who wish to examine the new
comet to wait until Mr.. Hind, who hat
long been recognized as the leading Eng
lish authority in matters cometic, has
marked out for the stranger the path
which it shall follow across the skies.
The comet which has just returned
is commonly called Winnecke's comet
having been discovered by that astrono
mer in 1858. 1t must not be cDnfounded
however, with q comet of the same name
which returned last year. The latter was
one of much longer period, and quite
different in character. The present one
travels once in FIVE and half years
round the sun. 1t was described in 1856
as having at first the appearance of an
underlined nebula, the light me at intense
in the center, bat no true nucleus to be
seen ; later a well marked nucleus made
its appearance.
1T must have returned in 1863, but
was not then favorsbly placed for obser-
vation. Indeed, little consideration
will show that a comet travelling in q
period of FIVE and half years can only
be we'll seen at alternate returns. If at
one visit it is well placed in the nocturnal
sky, at the next the half year difference
brings it on the diurnal sky, and OF
course the light of the sun blots out 80
faint an object, even when the most pow
eriul telescope is made use of In this
matter of its period Winnecke's comet is
not singular. More than half the comets
of short period take about five years and
a half in the performance of their cir
cult around the sun. The circumstance
is we'll worthy of notice, and has a very
interesting Interpretation. 1t arises from
the strange way in which the short period
comets have been twisted into our neigh
borhood by the planet Jupiter.
"This monstrous fellow goes on his
rounds like q gigantic policeman, and
takes up comet after comet, which but
for him would have passed far away from
the neighborhood of the sun. Sir John
Herschel has related in lively terms how
Jupiter i'll treated Lexelps comet, first
twisting it into the solar system, suffer-
ing it to go twice round the sun, and
then unceremoniously twisting it out
again, so that astronomers have never
seen it since. That was precisely the
sort of treatment which gives to comet
q FIVE and a half year period or there
abouts. For a comet which has thus
been forced into the solar system must
necessarily have the most distant part of
its path just outside of the orbit Of Mer-
curry; and that being so, the laws of plan
etary motion tell us its period must be
about FIVE and half years. The worst
of the matter is, that with an orbit so
placed comet is always apt to be sent
again upon its travels by Jupiter. If he
happens to be near st hand, when the
comet returns to the neighborhood of his
orbit, he will twist it out of its path as
easily as the Great Eastern would tow
cockboat. In fact, the way in which Ju-
piter treats the cosmicsl clouds which we
call comets merits for him the title of
cloud compeller, which Homer gave to
the Jupiter of Mount Olympus.
Altogether we congratulate ourselves
on the safe return Of the wanderer now
visiting our skies For it has happened,
quite recently, that our astronomers have
searched long and fruitlessly for one of
the same family We refer to the famous
comet named after Biela; the failure in
that case being peculiarly provoking, be-
cause the comet had presented the strange
spectacle at perfect division into two
distinct parts, and astronomers were
naturally anxious to know what might
be the results of this operation, after
complete revolution Of the twin system.
The present comet, though not quite so
remarkable an object, will doubtless at
tract a great deal of attention. Mr..
Huggins will probably obtain interesting
results by examining it spectroscopically,
and We have no doubt that il will not pass
away again into space without having
taught us some valuable lessons respect