Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1892-08-27
METEORlC SHOWERS.

| The display of meteors this month doe
not appear to have been greater than usual
There was. indeed, no special reason to ex
pect thatit would. except that popular fanc,
naturally connected them with the planet
Mars, with which. of course, they have moth
ing to do. The August meteoric display
which always takes place on or about Augus
10, appears to proceed from the constellation
Perseus, which is therefore known astro
nomically as tho radiant" and the meteori
Of this month are for this reason called
Perseids. In the Middle Ages they were
known as the "Tears OF st. Lawrence
Though the August display is increasing, II
10 not nearly 30 much SO as the November
display which occurs every SO years. the
meteors Of which are called Leonids, because
they seem to proceed from the constellation
Leo. The last display of Leonids occurred
on November n, in 1s66.T-'s, SO that the next
display will not occur until 1899.
The explanation Of this perio die display
is that there is long, thin stream oi
''meteoroids" distrib uted through space
each of which fs revolving around the sun
TSs isnssh of tnis stream Is
great that the most advanced members are
six or eight years ahead of those at the tai
end. They cross the earth's orbit with q
velocity of about % miles second, and, as
the earth meets them at an oblique angle.
they have q velocity of from 40 to 80 miles a
second when they reach the upper atmos-
sary to enter into here, says a writer in the
New York Tribune, the day when the Leonfds
are seen is moving along the calendar at the
rate of about month in 1000 years. In the
year 902 A. D., for instance, the display
occurred on October 13. An interesting
fact connected with the Leonids is that the
comet known as 1865 moves in almost the
same orbit. In fact, this comet is generally
r6par0ad n a N nd n
suggests that the Leonids may be portions
OF the comet which have been expelled
from 1t by some internal convuision. In
ofds are simply bits of disintegrated planets
seems to be entirely in line with what we
know OF the planetary system.
ANOTHER period when meteors may be
expected is on or about December Since
these meteors proceed from the constella-
tion Andromeda they are known as An
dromeds. All these facts prove that at cer-
tain periods the earth plunges through what
may be called rivers Of meteors whose posi-
tion and character are so well known that
the date of contact with them can be accu-
rately foretold. Moreover, 1t is pretty GER
tain that there are other streams of meteors
revolving through space whose "rad1ants"
are not yet known, but which may yet be
discovered. Further than that, it is likely
that the whole Of our solar system contains
q countless number Of meteoroids varying
In size from a more particle to bodies weigh
Ing several hundred pounds, all Of which re.
those which tall on the earth are called
meteorftes, and largo number of them are
to be found in collections in London, Paris,
Vienna, Berlin and various cities in this
country. They differ in some respects from
terrestrial matter. They are generally GOV.
cred with a thin, black crust, doubtless
caused by the intense heat to which they
have been subjected. Their outside surface
has evidently been melted, but SO rapidly as
not to Affect the inside. Sometimes one sur
face is only Drowned, indicating that there
atmosphere, and sometimes there fs only
crack. There are queer, cuplike cavities on
nearly all OF them, the cause OF which Is not
known.
METALLIC iron enters largely into the
composition of these lneteorites, and 1t is al
ways accompanied with nickel. When the
grayish interior, and exhibit a peculiar
globular structure. Occasionally meteoric
fragments have been picked up several
miles apart, which f1t together perfectly,
showing that they were originally one
piece. Generally the stones are too warm
to be handled when they fall, though cases
are on record in which they were very cold.
=
the distance. of course, depending upon
their momentu m and the softness of the
earth where they strike. Usually they are
not very large. stone of 100 pounds being
The total weight of stones found
after a fall has seldom amounted to more
than ], 200 pounds. Meteorites weighing an
ounce or less are most common. In the
opinion of the astronomers, the largest me-
that enter our atmosphere weigh at
the most Only q few thousand pounds, but
such bodies are almost immediately broken
up into ,Sn smaller 6Tdies oy the intense heat to
the more easy because of their generally
friable character. 1t is. of course, natural to
suppose that body which gives such brill
ant light as the shooting stars occasionally
give should be very large, because we in
3tin cttvely compare them with the planets;
but it is estimated that the smaller shooting
sand snd yst Be - arss enough to
Ill the light exhibited by them.
No NEW element has been found in the
a fact which goes far to indicate
that the planets of the solar system are all
of the same elements. The three
most common elements In these bodies are
ron, silicon and oxygen, which are the
;hree most common elements on the earth.
As to the number of meteors, Daubree esti-
mates that about 600 or 700 stones fall on the
Earth every year. The number of small
neteors, or shooting stars, is inconceivably
arge, and most, IL not all Of them. are
burned up before they reach the earth at
;hese particlesscome in contact with the
,arth every day. Thus, in addition to the
arger meteoroids, which are supposed to
loaf through space about 10 or u miles
part. the whole solar system appears to be
illed with small particles OF matter which
lave been most happily named "star dust"
FEW intelligent people need to be told |
hat the luminous appearance Of meteors |
md shooting stars is due to the heat pro- |
luced by their friction with the atmosphere. |
When they first appear it is estimated that |
hey are about 80 miles from the earth, and |
hey rarely get nearer to the earth than 25 |
niles. This, of course, does not apply to the |
arger stone meteors, whose weight causes |
hem to fall on the earth. That all the me- |
eors which we see are solid, and not gase- |
'us. is pretty certain, Tor gaseous body, |
yhen striking the atmosphere, would imme-
lately scatter and would not become lumi- |
lous. Nevertheless, there have been few, if |
my, fatalities due to the fall upon the earth |
# these bodies. The reason Is that the
lumber Of stones which actually fall on the
arth is very small compared with the area
# the earth. AS matter OF fact, we owe
,ur safety from these wandering |
,odies of space to our atmosphere, |
hey fall and spend themselves harmlessly. |
t used to be theory Of astronomers that
he meteoroids are constantly falling into
he sun in large numbers, and that they are
n fact its fuel, but that theory is now gen.
rally discredited, since it is found that the
neteoroids have their own orbit around the
un, just like the planets. Whether they
from the breaking up of former
,lanets by some great cataclysm, or whether
hey have always been thus floating throug gh
pace through the uncounted ages of eter-
lity, or whether, at some future point in
ime. they will be gathered together to form
ther worlds, are questions which will prob
bly, never be answered. The one thing GER
ain is that q study of them is one Of the |
most fascinating branches of astronomy.