The weekly ledger., 1857-05-30
THE JUNE COMET.

AT this particular time, the following re-
marks upon the subject Of comets generally,
from the Alta California, will be read with
peculiar interest at this particular time
These most wonderful of the cosmical bod
les that belong to our solar system, have, from
the earliest historic period, excited the wonder
and attention Of mankind Their extraordi-
nary and abnormal appearance-their rapid
and apparently irregular motions-the unex-
pected manner in which they burst upon the
unaSsisted eye, and the imposing magnitude
which they occasionally assume, have natural
ly conspred to render them objects Of aston
ishment and superstitious dread to the unin-
structed, and speculation and enigma to the
philosopher. At the present time no branch
Of astronomy is more replete with interest,
or more eagerly pursued, nasmuch as the
hold which exact calculation gives us upon
it, may be regarded as fully established
! Through this medium, comets have become
! the unexpected instruments of inquiry into
questions Of the profoundest Importance in the
theory Of the planetary system, and by means
Of the dissimilar eccentricity of their orbits,
| have, in the most brilliant manner, enriched
our knowledge Of the solar system.
! The feelings of awe and astonishment that
naturally excite the imagination upon the
sudden and unexpected advent Of great COM
cts, as those of 81 B. c., 43 b. c., A. d.
60, S37, l402, 1856, 1866, 1918, 1850, 1859,
l744 1869, 1911 and lS43, have not pre-
vented the diligent searcher into natures laws
from investigating the cometary elements I;
and we find that they are governed by the
same laws that retain the planets in their or
bts-that they shine by reflected solar light
that they have elliptical orbits-that by the
perturbations which they experience passing
near any of the planets, they have afforded
us the best means Of determining the mass of
| the planet-and, not least, that they have
established the fact of universal resisting
medium.
The nature of the cometary matter yet
remains mystery, but such is the extreme
tenuty of the tail, that the lightest cirrus
cloud floating in our atmosphere must be look
ed upon as dense and massive body, COM
pared with the barely visible texture of a
comet. Stars of the smallest magnitude
only seen in telescopes of great power and a
good defnition-remain distinctly visible, al
though covered by the deDsest portion of the
comet Halley's comet, in 1885, was within
two seconds of arc (the one-l000th of the
diameter of the sum of conjunction with a
star of the ninth or tenth magnitude; yet the
star remained constantly visible, and its light
was not perceptbly diminished, whilst the
nucleus of the comet seemed almost extn-
guished by the radiance of the star. Another
proof of the extreme tenuity Of cometary
matter is seen in the fact that the light of a
star, in passing through the densest portion,
suffers no refractlOn.
That the tail is an emanation from the nu-
ceus is an established fact; it developes as
the comet approaches its perihelion, decreas-
es soon afterwards, aud usually disappears
before the comet has attained the distance of
two hundred millions of miles from the SUM-
The rapidity of the increase Of the tail is
marvelously astonishing That of the great
comet of 1880, Immediately after its perihe-
lion passage, was found by Newton to have
been sixty millions of miles in length, and to
have occupied only two days in its emission
from the nucleus! Its greatest length was
one hundred and twenty millions of miles,
The comet of l744, which was so bright as
to be seen with the naked eye an hour after
midday, had six tails, spreading out like
fan and, about thirty-fve millions of miles in
length The tail Of the comet of 1850 was
iorty-eight millions miles in length; that of
the great comet of 1911 was one hundred
and thirty millions; and Chladin noticed a
rapid shortening and lengthening of the tail,
which amounted to several millions of miles
per second! velocity of motion (if motion
1t was) far exceeding that of light. The
comet of August 1853 presented similar
phenomenon. The tail OF the great comet of
lS49, whose appearance must be still fresh in
the memories of our readers, was one hun
dred and thirty millions Of miles in length.
The question Of the materiality of the tail
has excited the deepest investigation and
SPECULATION. The mind is almost bewildered
by the infinite sweep which it makes round
the sun in periheon, in the manner of
straight and inaexible rod, in defiance Of the
law Of grayitation, and even of the received
laws of motion. The tail Of the last men,
toned comet, was whirled, unbroken and
without distortion, through an angle of 1905,