The Pulaski citizen. [volume] (Pulaski, Tenn.) 1866-current, 1879-12-25
COMETS AND SHOOTING STARS.
The Distinction Between Shooting
Stars and Meteors-Their Veloci-
ty-ofWhat Are They Composed.

Stars and Meteors-Their Veloci-
ty-ofWhat Are They Composed.
| GProf. D. l.. Swift in New York Express. !
Meteoric astronomy now takes
rank as a distinctive branch of as
Economical science. Not forty
years have elapsed since it was as
certained that star showers are pc
riOdical. The accounts of the
showers that occurred in ancien t
times came down to us clothed in
snch extravagant language that IN
til the great star shower of Novem-
Der Is, 1888 astronomers were 10th
to believe them. Now they know
not only the cause, but are able to
predict their occurrence with al
most as much exactness as eclipses,
and the popular mind observes
these displays with equanimIty and
delight instead of fear and alarm, or
thinking the day of judgment has
come.
All know what q shooting star
looks like, but no living man can
tell US what it really is, torhnot one
has ever been known to reach the
earth. Those heavy, stony, and
still more weighty metallic masses,
called meteorites, meteoric stones,
ETC., which occasionally fall to the
earth, belong to another class OF
objects entirely, the origin OF which
man knows nothing.
A shooting star is only visible
while undergoing the process OF
com bustIon, which lasts from one
to three seconds, seldom longer.
Pevious to this they exist in a dark,
probably solid condition, not much
larger than peas, too small to be seen
by daylight, and in the night, being
in the earth's shadow, are eclipsed,
and consequently invisible. Only
while being burned are they visible
to us, as then they shine by their
own light.
Each meteoroid moves in an or
bit, revolving round the sun with as
much regularity as the larger plan
els. In fact, each is in every sense
of the word a planet, obeying strict
ly the laws of gravitation and plan
eJary motion. All space is filed |
with them; they are as numerous as
the sand. The earth and they in |
their journey round the sun encoun-
ter each other; the earth by its
attraction draws them to-
ward it, but to reach it they must
be drawn through the atmosphere,
which not one is able to do. Only
meteoric stones are able to reach |
the earth, and they have their sur
faces blackened and converted to
scoria by the terrible heat engen-
dered by the friction with atmos-
phere and by arrested motion.
Shooting stars move in all direc- |
tions, and at velocities probably |
equal to the earth's, nearly nineteen
miles q second. One moving retro
grade, therefore (irom east to
west), would plunge into the atmos-
phere at a relative velocity of some
thirty eight miles a second, and, if
be made for accelerated
motion, caused by the earth's at
traction, probably double that, or
thirty five miles a second. The en-
counter is fearful, and but for the
which acts as a cush,
on, the effect would be disastrous,
or not less than 800. 100000 would
ain upon the earth every day.
The source from whence these
neteoroIds come is comets, espec-
ally from their tails. The tail of
he great comet of 1911 was I50,-
10000 miles in length and l5,0O0,-
100 in diameter. 1t Is improbable
n the highest degree that the com
t could gather its tail TO itself
gain. 1t is left behind, forming
art of a ring, which in time may be
ONE continuous. Another comet |
ONES and it does the same, and
uring the ages which are passed, }
his process has been going on Till
be interplaDetary spaces are filled
18th not only meteoroids, but
still more marvellous.
In about three thousand years
ldb COuCS wiz AtAhA ~ AEaAl |
nd repeat the process, forming
art OF another ring, or adding TO =,
ne first, depending on circumstan y
es which need not be considered =
ere. Whenever the earth, in its !
nnual journey, passes through any "
ng made by some comet, no man Il
nows when, we get a star shower. -
he four most notable ones in our ;,
mes take place at the following /"
ates, viz, on the mornings of Au !,
lst IL and November Ii, and the =,
1enings OF November "a and 21. y
he last two are caused by the r.
nth passing through the track Of r,
eteoroIds left behind by the frag \,
ents of Bida's comet, which divi- g.
I'd into two parts in 184G. In this .,
ay meteoric rings are formed, of a
hich the solar system are filed,
ut none are visible TO US, except
lose the earth passes through.
y some such process was the Au- m
lst ring formed, which the earth b,
lssed diagonally through on the ca
-ening of the 10th and morning OF Ia
q IIth of that month. The comet ~
hich produced it was discovered M
: me on the 18th Of July, 1862 er