Barbour County index. [volume] (Medicine Lodge, Kan.) 1880-current, 1882-11-17
rhe Mrsterr Of Comets, Tail..

The cometary displays of the last two
years have excited in an unusual degree
the spirit of astronomical speculation
rs TO the causes of comets tails and
their mysterious movements. An In
glish scientist in the Philosophical Nag
GziHe propounds a novel theory TO ex-
plain these phenomena. The forces on
which he relies TO make out his theory
are the force of gravity which urges
the comet toward the sun, the expansive
force of the suns heat, and the resist
ance of an invisible atmosphere sur
rounding the sun at immense distances.
The changes i'm comet which give rise
20 its t~H begin with the emission of gas,
I'm the direction determined by the ex-
pansivc force OF the suns heat acting
on the comet. But soon these jets bend
round, as il carried back by strong
wind, forming an envelope round the
body of the comet and cone behind
IL. as would happen to man dressed
in n loose robe and running rapidly
agiust the wind. The jets of gas es-
Gaping from the body of the comet and
expanding whe2 they leave it are more
resisted by the suns atmosphere than
dts more solid heat. so that they seem
20 fall behind St, forming the comet s
envelope and conical form behind the
head. According to this view the boly
OF the comet is constantly moving
through the vapors it throws of, and
thus produces the appearance of tail
by leaving each successive part thrown
of more and more behind II. After
passing its perihelion the COMET carries
its tail before it instead of behind it, he
says, because while moving toward the
sun it is perpetually passing from a
rarer into n denser medium, while in
receding from the sun it is perpetually
passing from q denser into a rarer me-
dunn.
The fact that the most rapid altera-
ton in the direction of comets tails
necessarily occurs Just when the expan-
sive force of the suns heat is most felt
gives plausbility to this hypothesis.
There can be little doubt that, as Mr..
Higgins observes: elf we could see q
great comet during its distant wander
ings, when il has put of the gala trap
pings Of perihelion excitement, it would
appear as a very sober object. and con-
sist of little more than nMcleus alone"
The same may perhaps be said of the
mysterious wanderer while approaching
the sun, but not near enough to under
90 vauorizatiOn from the solar heat or
encounter the denser strata Of the
invisible solar atmosphere. The recent
inquiry of DIR. Siemens into the con-
servatiOn Of solar energy also lends COL
or TO the theory that comets when near
the sun may encounter n resisting medi-
nm, which would account for the phe-
a.
ferred TO suppOses. But astronomers
are yet far from solving the old prob
!ems of the origin and eccentric be-
haviOr of comets tails. There seems
to be-" says Mr.. Higgins. "a rapidly
growing feeling among physicists that
both the sclf-light OF comets and the
phenomena of their tails belong to the
order OF electric phenomena." This
view, in order to account for the carry
ing away of the comets tail under an
electric repulsion eXerted by the sun,
uecessitates the suppoSition that the sun
Is strongly electrified, either positively
Or negatively, and also that, in the
changes going on in the comet, the mat
tcI" thrown OFT by the nucleus has be-
come strongly electrified i'm the same
way as the sun. Otherwise the attrac-
ton on one side OF every particle of
:he comet would be precisely equal-as
Herschel points QUITO the repulsion
on its opposite side, and we should
therefore be at loss to explain the
enormous velocity with which the mat
ter of the tail is carried backward, in
opposition both to the motion it had rs
part of the nucleus and to that it nc
quired in the act of its emission. But
while all theories designed to explain
cometary phenomena have hitherto fall
EN- short of the mark, they have served
90 stimulate active investigation. and
also To throw important light on the
physics of the sun and the diffusion of
matter in interstellar space.-M y
Herald.