Perrysburg journal. (Perrysburg, Wood Co., O. [Ohio]) 186?-1965, 1881-07-15

There have been those who have no.
tually adopted the incrodible-I may
say the impossible hypothesis that the
tail rotated through this immense cir.
cult, developing centrifugal force
which all the united powers OF tho uni
verse could not have sustained. But
mol The comet practically left its tail
behind it, and began TO grow q new tail
as it receded from the sun. There were
thus two tails, nearly side by side
stretching from opposite sides of the
sun in nearly the same direction The
new tail began at the head of the
comet; whereas the old deserted tail
began without any head ut some dis.
tance from the nucleus, and extended
further from the sun than the new tail.
The nucleus of the comet is surround.
ed by mist, which is called the CONG,
or hair; the name comet signifying o
hairy star. The height of the coma
above the nucleus depends on the mass
of the nucleus, and gives the measure
Of its weight; or, moro exactly, the
least limit of weight which will suffice
to maintain such height of atmos.
phere. The nucleus is usually so close.
ly surrounded by the dense mist thai
its diameter cannot be measured; but
at times the mist rises, uncovers the
nucleus, and leaves it with q sharp
stellar aspect. The least diameter de.
termined ut such times may be larger
than the actual one, but cannot be
smaller. From the combination of mass
and diameter, the density of the nu.
cleus can be computed. In the case oI
Donati's comet, the diameter of the nu.
cleus was perhaps not more than hun
dred miles, while the height of the at.
mospherc extended to eighteen thou.
sand miles. You may be surprised to
learn that the corresponding density
of the nucleus was at least equal to
that of iron. What an unexpected
contrast is here presented to the prev.
alent notions concerning the sun and
the comets! The solid sun is reduced
by science to the state of gas, while the
substance of the ethereal comet is SOL
id and heavy metal.
In its approach to the sun, the sur
face OF the nucleus is rapidly heated it
is melted and vaporized and subjected
in its atmosphere with n well defined
servers as an envelope. Various envel-
| ODCS. CuCD OIutI, dEc
observed.
The eectriication of the cometary
mist is analogous to that of our own
thundercloud. Any portion of the
coma which has received the opposite
kind of electricity to the sun and to
the repclled tail will be attracted. This
gives simple explanation of the mega
tive tails which have been sometimes
seen, directed toward the sun. In cases
of violent explosion, the whole nu-
cleus might be broken to pieces, and
the coma dashed around so as to give
varieties of tail, and even multiple
tails.
The relations of the comets to the
solar system present ali interesting and
instructive study. With very few ex-
ceptions, their visible paths are so near
ly parabolic, and the positions of their
nuclei and centers of gravity so uncer.
tain in the midst of their come, that it
is quite out of the question to obtain
nice enough data to measure exactly
the extent of their orbits, and ascertain
how great may be their deviations from
exact parabolas, and whether the devil
ations are such as to make them ellipses
or hyperbolas. If an orbit is actually
parabolic or hyperbolic, and if there is
no decrease in the central attractive
force as the comet approaches the sun,
it must have entered the solar system
from outer space, and cannot be one OF
our permanent partners. 1t will leave
the system again, and we NAV never
expect its return; unless, indeed, hav-
ing passed through the circuit of other
suns, after myriads of years, it reap
pears in an orbit entirely different from
its former one, so rs to afford no evi-
dence through which it may be recog-
nized. But ifit moves in an ellipse, and
does not leave our system, it will return
in sensibly unchanged orbit, through
which it may be detected
The astronomer is often asked, upon
the announcement of comet, "Is it a
new onep" and the tone of the inquiry
usually implies feeling of Satisfaction
in witnessing the discovery of new
star. But it is just the reverse with the
astronomer himself. He ransacks the
records, hoping against hope that he
may enjoy the good fortune of ascer.
taiuing that the new comet is an old one
old, at least, in the sense that it has
been observed once before, but moi
twice. On its first temperance 9
comet is certain to be loaded with the
name of the geometric discoverer of its
path. Its theory is computed; its future
returns are rigidly predicted; its socia
position is definitely established, and il
takes its place among the registered
members of our constellation. But {
comet may belong to our system. anG
yet go so far from the sun that the in
| tnryalg hntpVaan its rNarinIc ,fy yrt,;bi1st,
may be rs long as three hundred thou
sand centuries.
There are few comets of which the
nonparabolic character is evident a
once. Their orbits are decidedly elliptic
al: their periods do not exceed baker
dozen of years; and they are intimatel,
; related to the plants in their position.
and direction of motion. Prof. Newton
of Yale College, has given distinc,
and satifactory explanation of the mode
in which these comets were probably
diverted from their original paraboli,
paths by the action of the plane
Jupiter. 1t was royal sport, and tn,
final. character of the cometary orbi
was the natural termination of tn,
game. These comets must be excluded
from our general discussion.
Omltting Them, we ma nothing II
the position of the other orbits whicl
indicates relation to the solar axis O
rotation or to the planetary planes o
revolution. They are rs uniformly dis
tributed as il they had entered ou
system indillerently from every direc
tion, and without reference to the pre-
vailing motion of the planets or to thei
mutual organization. They are simpl,
the largest of an immense swarm O
meteors which are floating all arount
us--a swarm of which by far the create
portion consists of bodies too small to b,
. seen bv the light thrown upon then
from the sun; and this invisible portion
greatly surpasses, in number and evel
: in combined mass, all the VISIBLE com
: ponents OF our constellation.
Returning to the original round neb
ula, from which the solar system wa
, formed, we must suppose that it ha
L. i