Massachusetts spy and Worcester advertiser. [volume] ([Worcester, Mass.]) 1823-1825, 1824-02-04
The Arts a1rn SctfMre9,
COMETS.

The following remarks are extracted from
an English work. They refer to some obser-
vations which had been made by DR.. Hershel,
on the Comet of 1911.
The Comet of 1907, 10 its approach
to the sun advanced within sixty-one mil
LIONS of miles Of it. and its tail, when
longest, covered an extent of nine mil
lions of miles. The late comet, in its
perihelion did not pass so near the sun
by about thirty-slx millions of miles, be-
ing about two thirds only of the closest
approximation ofthe preceding, and new
ertheless acquired tail of upwards of
hundred millions of miles. May we not
then conclude, as he suggests, that the
consolidation Of the comet of 1907, when
1t reached its perihelion, had already
been carried to "a much greater degree
OF density than that of the last comet, by
some former approach to our sun, or
some similarly constructed celestial bod
les, such as we have reason to believe
the fixed stars to be? And that comets
may pass round other suns than ours, is
rendered probable from our not know
ing, with certainty as yet, the return of
more than one comet among the great
number that have been observed?
Deguignes enumerates two or three
hundred comets mentioned by Chinese
writers. Doubts, however, have since
been thrown upon the authorities refer
red to.
Extensive as are orbits of comets,
from their eccentriclty, they have some
times approached much nearer to the
sun than any of the planets; for the
comet of 1880, when at its perihelion,
was at the distance of only one sixth of
the suns diameter from its surface. Yet
from the very inconsiderable density of
their enormous tails, and even of the
greater part of the nucleus itself, should
it ever happen to planet, of which
there is very little probability, to fall ex-
actiy in the way of d comet, it is suppos-
ed that the inconvenience suffered by
The inhabitants of the planet might be
merely temporary and local: the chan
ces are, however, much greater, that a
comet might interfere in such manner
with aplanet, as to defect it little from
its course, and retire again without COM
ing actually into contact with it.
Nearly 500 comets are recorded to
have been seen at different times, and
the orbits of about hundred have been
correctly ascertained: but we haye no
opportunity of observing sufficient por-
ton Of the orbit of any comet, to deter
mine with accuracy the whole Of its
form as an ellipsis, since the part which
is within the limits of our observation
does not sensibly differ from the para
bola, which would be the result Of an
ellipsis prolonged without end.
Two comets at least, or perhaps three,
have been recognized in their return.
A comet appeared in ITO, which Pros
perrin suspected to move in an orbit ma
aerially different from parabola. Mr..
Aexell determined its period to be 5
years and months, and its extreme dis
etances 10 be between the orbits of Jupi-
ter and Of Mercury; but it does not ap-
pear that any subsequent observations
have confirmed his theory. 1t has, how
ever, been calculated that, supposing
ahe theory correct, it must afterwards
have approached so near Jupiter as to
have the form ofits orbit entirely chang
led.
Dr.. HALEY foretold the return of the
comet about 1853, which had appeared
ini53l, 1907, and in 1852, at intervals
of about rs years; and with Clairaunt's
further correction for the perturbations
Of Jupiter and Saturn, the time agreed
within about month. The mean dis
lance of this comet from the sun must be
less than that Of the Georgian planet /;
so that by improving our telescopes still
more highly, we may, perhaps, hereaf-
ter be able TO convert some Of the COM
cts into planets, so far as their remain
ing always visible would entitle them 10
the appellation. DR.. HALEY also sup
posed the comet of 1880 to have been
seen in 1905, in 53l, aud in the year "A
before Christ, having a period of 575
years. and il has been suspected that
.sthe comets Of 1856 and 1854 were the