The Nevada Democrat., 1858-12-15
The COmet-VVhat IL has seen--And What Is
TO be said about Comets In GeHeral.
Tl'om De London 4

ago. AS that is the ascertained minimum, and,
on very elaborate calculation, 2,495 years
the ma1tnIum of the journey which the Comet
has done since his last appearance here we
know that it occurred during that period of
history which is most interesting and best known
to most of US. Englishmen know ancient his
tory better than modern, and the affairs Of
Rome, Greece and the Eastern Empires better
than those Of any existing State So we might
! feel almost at home with this Comet, and well
come it as an old friend. It might, ct its last
appearance, have terrified the Athenians into
accepting the bloody code of DRAco. 1t might
have announced the destruction Of Nineyah. or
Of Babylon, or the capture Of Jerusalem by Me-
BUCHADNEZZAR. 1t might have been seen by the
expedition which sailed round Africa in the
reign of PHARAOH NECHo. 1t might have given
interest to the foundation of the Pythian games.
Within the probable range of its last visitation,
are comprehended the whole Of those great
events and personages that constitute what we
call the history of Greece, from her early strug-
giles with Asiatic despots to her subjugation by
Rome In the annals Of the later Power we
have the whole period from ANGUS MARTIUs and
the destruction Of Carthage to choose from.
| Beyond doubt, however, at some time or 9TH
er in that period SO familiar and so dear to
most of us, precisely the same sign was seen in
the skies. Among its spectators might have
been not only Kings aud conquerors famous in
story but the so-called sages of Greece and
even the prophets of Holy Writ THALEs might
have attempted to calculate its return, and JER-
EMIAH might have tried to read its warning.
But how different the Significance of the won
drous sight at the two periods Till modern
times the boldest conjecture never placed COM
cts SO far as the moon; and the prevailing be-
| lief was that they we're rather meteOric than
celestial bodies. Thus they were described as
hanging over a doomed city, and marking the
very site of Divine visitation. They were
naturally compared to flashing scmeter or
the burning brand. The very expression is,
that comet blazed in the sky. We are not
aware that it ever occurred to astronomers till
two or three centuries ago that comets return
ed, the variety in their appearance produced
| by the different places of the earth in its orbit
being quite enough to battle any attempt to
identify them. No sooner was 1t found that
comets are in fact planetary bodies, revolving
round the sun by the same law as ourselves,
than speculators ran into the other extreme,
and fondly hoped they might be links between
| this system and some one other, or might even
wander through the universe, visiting first one
star, then another, to all time. Modern eel
ence, however. establishes that the range Of
our present visitor, though immensely wide
compared with our planetary proportions is
straitened indeed compared with stellar distan-
ces. He had his tether in the attraction of the
sun, as we have. He can travel, indeed three
hundred and fifty times further from the sun
than we can, and about twelve times further
than Neptune, the most distant and last discov-
cred planet of our system; but even this does
not carry him One-thousandth part OF the dis
tance of the nearest fixed star. Let any one
take q half-sheet of note paper, and. marking
circle with a sxpence in one corner OF it, de-
scribe therein our solar system, drawing the
orbits of the earth and the inferior planets az
small as he can by the aid Of q mAgnfying
! glass. If the circumference OF the sixpence
stands for the orbit Of Neptune, then an oval
filling the page will fairly represent the orbit
of our comet; and If the paper be laid on the
pavement under the west door OF st. Pauls,
the length of that edifce will inadequately rep
resent the distance of the nearest fixed star.
That the comet should take more than 1000
years to travel round the page Of note paper
we have supposed, is explained by its great dim
mutton of speed as it recedes from the sun. AT
| its perihelion, or as we have seen it move late
ly, it has travelled l27 900 miles an hour, or
more than twice as fast as the earth, whose mo-
| ton is about a thousand miles q minute. At
| its aphelion, however, or its greatest distance
! from the sum- the comet is very slow body,
sailing along, as il doubtful whether to return,
at the rate OF 4S0 miles an hour. This is only
eight times the speed Of q railway express. At
this pace, even If the comet could wholly shake
off the attraction of the sun-which it certainly
could not--and were it to travel onward in
straight line, the lapse of million years would
find it still travelling balf way between our sun
and the nearest fixed star. Comets then, can
hardly be imagined visitors from our system to
any other, or from any other to our own. There
is every reason to believe they belong to us,
and are only planets Of lighter material. less
settled construction, mere eccentric orbits and
somewhat more devious path than our own SOL
id globe.
Comets are the very cruz OF astronomers.
Every science has its difficulties; policy its cri-
sis; history its mysteries; medicine it's incura-
bic diseases; surgery its deadly operations; life
itself its great trials. But Comet seems to
combine In one all the difficult problems Of OBJ
servation and calculation. Though it cannot
but move by the same laws as our own planets,
yet the ell lipse is sol immense and the course
homeward towards the Sun 80 straight, that 1t
is necessary to make the false assumption OF
parabolic motion. The true ellipse, however,
ascertaned. the difficulty does not cease; for
the Comet is so disturbed by the attraction OF
the planets near which il successfully passes
that the orbit of one day is contradicted by the
orbit of the next-curve, velocity, period, dis
tanee, all changing from hour to hour. Even
when we know, as we do with regard to HAL
LEr's Comet. its history for two thousand years,
its orbit for all that time, still at every fresh
return the Comet suffers planetary disturbances
which affect it forever. But the material, tho
construction, and the internal history of Com
cts are still more inscrutable. The utmost OBJ
seryation and research have failed to discover
anv weight in them. The Comet now receding
from our view passed on Monday within nine
million miles Of Venus, and if it had any dem
sity at all comparable to our own would have
effected the orbit of that planet 10 an apppreci-
able degree. Were that found to be the case,
II would be the first fact Of the kind in the his
tory of these singular bodies. But, even II
there we're no weight in Comet, it might still
be of very Opaque matter. is, however, by
no means certain that the very nucleus can IN
tercept the light of small telescope star Yet
in this light transparent substance, is the
source of the immense tail, which in some COM
cts has been hundred millions, and in the pres
ent instance, not less than forty millions OF
miles long. 1t is the seat Of the imost extraor-