San Antonio daily light. [volume] (San Antonio, Tex.) 1886-1907, 1893-11-13
MISSILES FROM THE HEAVENS.
Billions of Them Fall, but Comparatively
Few Reach the Earth.

Few Reach the Earth.
sit is mistake to suppose that mete-
orltes burst IN the proper sense of the
word" said a scientist to writer. But
it often happens that they are broken to
pieces on striking the atmosphere of the
earth. This may seem surprising, but
let me call your attention to an analogy.
Strike the surface of water with your
fist, and, though a fluid, the resistance it
opposes to the blow seems almost as
strong as if it were solid. Now, the me-
teorite is moving at a tremendous rate of
speed. If small, it is set on fire in an in
slant by the friction of the air, and after
glowing for a moment brightly is con-
sumed.
ION any night in summer you will
see shooting stars now and then. They
are meteorites, which on coming into
contact with the earth's atmosphere are
set-afire. This is not surprising, mas
much as they approach the planet on
which we live at speed which often at
tains A miles a second. BY causing the
destruction of meteorites the atmosphere
serves as a protection for people on the
globe, who would otherwise be pelted
by such missiles to a dangerous extent
1t is estimated that not less than 10000
600 of them, big" enough to be visible to
the naked eye, strike the earth every "a
hours.
by contact with this planet the me
teorites are raised to a temperature which
nnh frnr1n 70 4 Il
grees-high enough to consume the hard
est known substance almost instantly
Thus only those of large size reach the
earth before being entirely burned up.
The greatest number of such bodies can
be seen just before daybreak. because by
that time we are ON the front side of the
globe as it moves through space. The
elevation at which most of them are Wis
ible has been found to be between 4J and
so miles, very few being seen at a greater
height than 100 miles.
at is believed by most astronomers
that some very large meteors have ell
tered our atmosphere and have passed
out into space again, their great mo-
mentum being sufficient to take them
away from the earth's attraction. What
these flying bodies are is question that
has been much disputed, but it is con-
sidered most likely that they are the
debris of broken up comets. In one re-
cent instance the correctness of this the
DRY has found striking proof. That was
the case of the comet of Biela. 1t was
discovered in 1926 and was again OBJ
served in 1882, 1915 and 1852. In 1916 il
had split into two parts, and i'll 1872 il
failed to appear when and where ;t
should have done. Evidently it had been
smashed up. and prediction was made
that there would be a great meteOric
shower composed of the remains Of the
lost comet. This prediction was fulfilled
Certain groups of meteOrs move in
elliptical orbits around the sun. Occa,
sionally the earth passes through their
clusters, producing what are known as
meteOriC showers. Such showers occur
annually from the 9th to the 18th of Al.
gust, and there is a similar display IT.
November once every 80 years. The
stream of the August meteOrs is est
mated to be from 100000 to 10000. 900
miles thick. The earth, though travel
ing with the velocity of 100000 miles q
day, is immersed in it for several days.
The fall of meteOrites to the earth is
sometimes accompanied by great dis
play of light, occasionally Illuminating
an area of many thousand square miles
When such an event occurs at night, and
with loud detOnations, so great in some
instances as to shake houses and fright
Ell men and animals, the explosions are
caused by the breaking up of the me-
teor. Ordinarily you will find that such
meteOric bodies are coated on the out
side with a black substance, which is
the effect merely of fusion of the super
fetal material by great heat. A piece OF
Biela's comet was actually picked up in
Mexico in 1872 at the time Of the shower
of its remains. Naturally it isconsid-
cred interesting.
"SuCh great interest is taken in metc-
Orltes that all Of those collected have
been carefully catalOgued. They are
mostly composed of iron, with usually
percentage of nickel and cobalt and
sometimes copper and tin. 1t is custom
airy to saw them into slices, which is II
labOriOus process, for sale or for eX-
change among museums. Sometimes
the slices are prettily polished, or the cut
surfaces are etched, with acid so as to eX-
pose the crystalline structure. This
structure is in no two such bodies exact
" the same. and the differences are