St. Paul daily globe. [volume] (Saint Paul, Minn.) 1884-1896, 1884-11-15
WHAT COMETS ARE.

In a recent article in Science" on the
distribution Of comets, there are some fea-
lures OF interest to all those who have taken
any thought Of these celestial visitors. OF
the multitudes Of comets that have been re-
corded not ali are Of that type which has so
often startled the unthinhng inhabitants Of
the world either filing them with apprehen-
sion by a sudden aud pretenrous appearance
In the sky or rousing in them for the mo-
ment an Interest in the wonders that lie
about Us. The majority now discovered fur
nish only theme for the astronomer and a
subject 10 which be can apply the resources
OF his science for the Advancement Of that
science itself. SO much of his work IL Of the
same nature that be is often looked upon as
entirely an impractical man, a devotee Of an
art ironically described as too sublime for
the vulgar to comprehend. Bait one should
not lose sight OF what has been done for the
practical objects OF navigation, surveying
and even 80 ordinary an affair as the regula-
ton Of our measurement Of time by the work
of astronomers in the fact and though the
details Of such work may have been reckoned
Of slight account by others living at the time,
to them We owe much OF the present perfec-
~
small number of new comets are reported
merely to the general public, which could
not be expected 10 care for more, bat to the
astronomer each is source o. interest and
its welfare Is looked 10 as carefully as may
| be, con sidering the great distances at which
these strangers hold themselves aud how anx-
ious they would seem 10 be TO take their de-
parture from the family Of planets, among
which they have become entaneled.
Probably not less than i've thousand com
cts large enough 10 have been seen with our
present appliances and quite likely 10 have
been picked uD by the searchers OF our day
IL the search had been kept up as vigorously,
l have entered the solar system since the be-
ginning OF the Christian era. Could we
know as much Of AL these as We do Of the
few that have been observed since the per-
feetiOn OF the methods now in use there
would be light no doubt on many obscure
points. Two hundred and eighty-fye orbits
can be found of comets which have been
well enough observed to render It possible to
compute an orbit. By these the astronomer
can trace the courses of any Of the old COM
cts, not only during the period while they
were visible 10 the star gazers OF he time,
but before they had come into view at all and
after they bad vanished from sight It is
thus quite possible 10 determine the direc-
before entering the planetary system. bot
with this direction he must for the present
stop; he can as yet go no further. While
there are still many mysteries In our solar
system yet TO be solved, Of the universe be-
yond its limits we know almost absolutely
nothing. We determine the directions OF
the stars, but the problem of their distances
will never, in all probability be solved with
much approach 10 certainty WITH all that skill
in the making and use of instruments can
accomplish.
Meeting ship in mid-oeean, catching the
hrst view when it is on the distant horizon,
as 1t passes TO vanish beneath the rim Of
ocean astern one gets the course of the stran-
ger aud from its appearance might hazard a
guess as to its port Of departure and destina-
ton. These could be definitely settled we're
it known to be holding 10 an invariable
course, uninfuenced by wind or current and
not liable 10 collision unforeseen in advance
Nothing in the appearance Of a comet
| gives us any clue as 10 its origin, but we do
know that 1t is ooeying the same laws under
the sway of which the earth swings on its
course and as long as it remains within the
influence of the sun, the ruler OF the planet
airy motions, the comet yields itself TO the
same authority. At what distance the sun
first begins TO exert this authority or what
forces have been in control of the comets
before the revolution by which they have
thrown of their old allegiance to accept the
hazards OF a new can not be determined
And there are hazardous epochs in the
short life of many comets in the life of which
the history can be written. Their paths may
bring them close to one of the big planets,
whose attraction shall whirl them of their
| previously adopted orbit into one that will
keep them revolving about the sun until
such approach shall twist them of TO recede
into outer space. This would correspond to
= certain extent to a collision in space 10
say nothing OF the chances Of an actua
meeting face to face with one OF the planets
Of which chance our earth comes in for a
share one in 4 few billion or so. Then il
they have not taken course that will bring
them very close TO the sun they are TO be
subjected TO degree of heat beyond COM
parison with 'our standards for molten metal,
even while the SUMS powers will likely de-
prive the comet of material enough to form
tail, which will be scattered far and wide to
form possibly meteoric display.
The direction only, then, from which the
comet comes Is TO be determined and while
they may have come to US from any of the
stars beyond the fact that there NAV be a
star in the same direction, more or less close
perhaps to several comets, nothing can be
definitely asserted. Through the realms OF
space comets are scattered with profusion
apparently inexhausuble. II there are no
regions especially rich in supplies. aud IL
there are no causes by which more would be
drawn from any special quarter We should
expect 70 lind the points representing the
origins or direction from which the comets
have come evenly distributed on all sides of
Us. There are groups of points OF origin,
whatever the cause OF these groupings may
be, too frequent to be accidental in an equal
distribution; and while the known points
form too small proportion OF all that must
have been established unknown to human
investigations, TO draw any reliable conclu-
sion, some effect seems 70 be traceable 10
the motion of the solar system itself in
space. Without going into this matter, ii is
enough 10 state that based on the small but
well-determined movements OF the stars as
seen from the neighborhood OF the sun.
which is but star itself, the direction of the
motion OF the sun among the other stars Is
considered known within no great uncer-
tainty.
The amount of the motion Is not great
enough to affect the supply Of comets by ex-
hausting any region, but il does appear that
taking equal areas situated IN a correspond
ing manner In the quarters respectively from
which and TO which he sun Is moving. car
rying with 1t the planets and all comets fully
under its sway, more come In from the areas
behind. Moreover-and this consideration
is not Influenced TO the same extent by the
lack Of material, since 3 fair portion NAV be
considered as giving in general indications
those coming 10 from the regions behind
on the average pass closer to the sun when
they oyertake IL