Southport telegraph. [volume] (Southport, W.T. [i.e. Kenosha, Wis.]) 1840-1850, 1843-04-04
From the Boston DaiIv Mail.
COMETS.

COM ELS.
The splendid COMET which is even now
coursing It's way in its eccentric and elipti-
cal orbit, through the heavens, in full sight
Of our own planet. has been vie wed by
thousands, and has excited deep interest
on every thing that relates to such pheno-
mena. The newspapers far and near,
catching as they always do, because it is
their interest so to do at every thing up
permost in the public mind, are giving TO
tho subject ofsuch phenome Ma that consid-
Grafton which it is calculated to inspire ;and
numerous enough are The remarks and
essays which we ind in our exchange,
graduated, of course, in their extent or pro-
fundity, but the knowledge of the resPec-
tive editors.
From a series of interesting articles on
the subject in the Vermont Mercury, we
have gathered in condensed form a good
many facts which may be interesting TO our
readers at the present time. The periodi-
cal revolutions Of several of the comets have
been determined with great accuracy, and
their predicted returns have verified the
truth OF the calculations. 1t is true, that
in some cases the return of comet has not
fully verified the correctness Of the COM
putation. This does not, however, prove
that the elements Of the calculation are not
founded in truth, but it goes to prove, or at
least tends 10 indicate, that there are influ-
ences acting on the Comet in some portion
Of its immense orbit, Of which the astrono-
mer is at present ignorant, and which may
be developed by farther progress in the
onnOhliDo Scianco Of Sfropop,r
The number Of Comets belonging to the
solar SYSTEMS probable vastly greater than
has been generally supposed Mr.. Arago
has computed their number to be about
seven millions.
In respect 10 the tail, or luminous train
which generally accompanies comets, j, is
found that it is generally in opposition to
the sun, or on the proongaton Of the line
which would join the sun and the nucleus.
But this is not always the case. Some.
times the direction Of the tail has been Mt
right angles with this line;and in some ex-
traordlnary instances, the tails Of comets
have been observed to point directly towards
the sun. In general however, it is found
that the tail nclincs constantly towards The
region last quilted by the comet.
The most remarkable instance Of a divid-
ed tail was in the comet Of 1744 On the
9Th and 18th March there were six branches
in the tail, each Of them about 4 deg. in
in breadth and from 80 to 40 deg. long. The
tails Of comets sometimes cover an immense
space in the heavens. The comet Of 1886
had tail which extended TO 69. deg. that
Of 1911 to 29 deg, and that Of 1869 10 81
degrees in length; SO that some Of these
tails must have reached from the zenith 10
the horizon.
According to Schrtetet's observations
and estimates, the diameter Of the nucleus
Of the comet Of 1907, was 1900 miles, and
the diameter Of its coma. (the haze or ne
bulosity which surrounds its nucleus, l20.-
600; and its rate of motion, at certain
periods, 1913 $50 miles day, or So 551
miles an hour. But what was deemed
most remarkable was the variation in
length and the coruscatons Of the tail. In
some Of the observations, the steamers
shot from the whole expanded end Of the
tail, sometimes here, sometimes in an in
slant, two and la half deg. long,so that with
in single second they must have shot cut
a distance of 1900 600 miles.
The periods Of some comets are said TO
be many thousand years, and even the ev-
erage time Of the revolution Of comets gen.
orally is about a thousand years; which
proves that the suns gravtating force eX-
tends very far. La Place estimates that
the solar attraction is felt throughout n
sphere whose radius is a hundred millions
Of times greater than the distance Of the
earth from the sun.