The Iola register. [volume] (Iola, Allen County, Kansas) 1875-1902, 1883-10-26

of few hundred miles; and these, in
the form OF meteors and shooting stars,
are rushing through space, dropping
continually upon the larger worlds, in
creasing their size, and adding to then
store of heat and energy. Every veal
the earth encounters nearly three thou
sand millions of them, according to the
estimate of Prof. Newton. ranging from
the merest particles to masses of sever
al hundred-weight. Very probably
also, the comets belong to the same
category, being really nothing but
larger meteors, or tiocks of small
meteors, or perhaps even only
puffs of meteoric dust. Nearly al
meteors which strike the earth are yer,
minute. Perhaps a hundred or so react
the ground each year as recognizable
masses of stone or iron, weighing from
an ounce or two to some hundreds Of
pounds, but all the rest are dissipated in
the upper air, and never come down un
less as impalpable dust, not to be GER
tainly identified. The whole amount
of matter falling daily upon the earth
from outer space is probably about one
hundred tons on the average Git is vari.
ously estimated from twenty-five to five
hundred). A hundred tons is in Itself
a very considerable quantity, but utter.
ly insignificant as compared with the
mass of the earth. and entirely inca
pable of appreciate effect upon oul
temperature. Assuming even the largest
estimate Give hundred tons day. land
also that the average velocity with
which meteOrs enter our atmosphere is
fifteen miles second (probably con-
siderably too large). we find that the
heat annually received from them by
the earth is only about fiftythree calo-
ries for each square meter of her sur
face-less than would be impaired By
two minutes perpendicular sunshine,
and only about 1-60, COO of the heat ac-
tually received from the sun in year.
Retaining the same eXtravagant estimate
of five hundred tons a day, it appears
that the earth's diameter would grow
an inch in about one hundred millions
OF years, and that her distance from the
sun would be reduced about eighty
three feet in million years, in cOnse-
quence of the resistance experienced in
moving through the meteoric swarms
1t would not, however, be Just to the
generalreaderto dismiss the subject with
out ia r notice that some most eminent
astronomers hold views at variance with
those above expressed. The late Prof
Peirce maintained to the end that the
heat of the sun is chiefly due to the i'm
pact OF meteors, and also that the earth
itself receives as much heat from meteors
as fr' m the sun, a necessary result if
the solar heat is really SO produced. Of
course we have no space to discuss the
matter here, and must be content with
merely saying that the quantity of mat
ter which falls upon the earth, if his
idea is correct. ought to be easily no.
ticeable. amounting to about fifty tons a
day on each square mile. 1t involves
also serious difficulties in the planetary
theory.
So fara human beings are concerned,
the most important question connected
with our subject is whether ANYTHING is
TO be feared from comets. as a conse-
quence either of collisions with the earth
or of their fall into the sun. 1t may be
said, just as of the stars before, first,
that cometary collisions either with sun
or earth, must be very rare occurrences;
and. secondly, that they are practically
certain to happen some time or other.
Babinet computed, on the one hand,
that comet would strike the earth on
the average about once in 1900. 900
years; on the other, we know at least
three comets whose orbits cut the
earths path so closely that if they
should ever reach the crossing at the
same time as the earth a collision must
occur. These comets are known as
Biela's. Temples, followed by the Leo
mid meteors in its train, and the comet
of 1862, which precedes the Perseids.
One of the three, however Biela's), has
probably ceased to exist as comet,
and it is quite possible that the other
two may vanish in the same way before
we meet them.
As to cometary encounters with the
sun, no comet has vet been known
actually to strike the sun, but several
have grazed very near it. The great
comet of last year brushed through the
corona, and came within three hundred
thousand miles of the photosphere, and
there Is no assignable reason why some
other comet should not actually pierce it.
As to the consequences OF a comets
with the earth, it is impossible
to predict them with scientific certainty;
probably, however. they would be insig-
nificant. We know absolutely that the
whole quantity of matter in comet
technically. its "mass'') is extremely
small compared with that of the earth;
but just how small no one can say. II
Is impossible to contradict authorita-
lively either the man who says he could
carry comet home in his pocket il
properly packed, or one who asserts that
a comets nucleus is equivalent to an
iron ball one hundred miles in diameter.
An attempt has been made to get at the
density of the central nucleus on the as
that it holds to itself the enor-
nous volume of the head and envelopes
by its gravitational attraction, as if the
surrounding nebulosity We're an atmos-
phere in equilibrium around the nucleus:
but the assumption is more than doubt. |
ful, and the derived conclusion, OF
course, is of little value. 1t seems, on
the whole. more probable that comet |
S throughout only cloud of dust and
1apor-a mere smoke wreath-than that |
here is at the center any solid kernel Of
mass.
Ii a comet really has at the center
my great mass of stone or. iron, or even |
close-packed swarm of aerolites
ton or two apiece, collision
With it would of course be a most seri.
'us matter. spreading devastation and
possibly over half the
slobe at once: not amounting, proba-
'ly, to anything like destruction of the
world, but far more disastrous than any
earthquake or volcanic eruption. 1t is
ar more likely, however, that the en-
counter with comet would be entirely