The herald., 1894-02-14
MESSENGERS FROM |NFINIfY.
A Lecture on Meteorites and
Shooting Stars.
What They Are and Where They
Come From.
Pieces OF Planets Expelled bv Volcanic
Force-Only Thousand Observed
Falls-The Great COL
Iections.

IIol. w liiiaIu II. might l0CbuIbu ldbb
night before the Broadway club, at the
First Presbyterian church. on Meteorites
and Shootingstars. In part he said:
Having by his importantly thus
wrested these great secrets from the uni
verse, nature again smiles upon man s
efforts to invade her distant realms, and
graciously sends messenger from those
starry depths, lands it at his feet, bids
him examine, analyze, and test it in
every way, to prove by the tangible evil
dence Of his senses that the great worlds
wheeling in distant epace are akin to
ours, that matter is identical and indie
structible, and that law is universal and
irrefragable.
For meteorite ia such a messenger.
In the morning of creation, when Ju-
piter, Saturn and Neptune were burning
suna like our central luminary, masses OF
matter were constantly elected from
their seething interiors by volcanic
force. The material thus expelled some
times passed beyond the limit of the
parent planets attractive power, and
condensing into meteoroids, these for
ever afterward revolved in elongated or
elliptic orbits of their own, more or less
eccentric, according to the angle at
which they were shot from the plane of
the planets orbit. And so for uncount-
ed ages this meteoroid has swung along
the mighty ellipses. now in the burning
nei2hborhood of the sun, and now in
the lonely darkness OF interplanetary
space. Finally, in its last fateiul jour
fNx w1e han ,k.,u - o&a.,,
passed 30 near the earth az to dart
through portion of its atmosphere. Its
amazing speed of 80 miles per second
condensed the air before it, producing
an intense heat that instantly changed
the temperature OF its surface from hun
dreds of degrees below zero to atato of
high incandescence.
If it was stony meteor and came
within 80 miles OF the earth's surfacs its
outer layers scaled off with terrific ex-
plosions and precipitated portions of
the meteoroid to the earth, while the
main body passed on perhaps into cos
mic space. A meteor, then, or meteor
old. is body moving about the sun in
elongated ellipee and ultimately making
itself luminous by impinging upon our
atmospheric envelope. A meteorite is
fragment OF that meteor, thrown off
by the explosive force of sudden and
enormous change of temperature on its
surface.
Shootingstars are very small meteors
| 80 minute, that in passing through
portion OF our atmosphere they are ar
rested, practically burned up, and
slowly settle to the earth in an impal-
pable powder,
Meteors, then, and meteoroids, meteor
ties, serolites, bolides, freballs, shoot
| ingstars and fallingstars are the various
names applied to different phases OF the
same phenomenon. They are bodi es
ranging in size from particle OF cosmic
dust to vast globe q mile or more in
! diameter, coming from the regions OF
planetary or interstellar space, and
sweeping with marvellous velocity into
or through portion OF our atmosphere,
becoming suddenly and highly incan-
| descent.
The fall OF meteorite is usually pre-
ceded by an explosion, sometimes sew
eral. The noise has been compared to
thunder, and also to artillery. 1t is pro-
duced in regions where the air, highly
rarifed, very imperfectly propagates
aound, proving that its intensity sur
passes all else known to us.
You who burn Black Diamond coal in
an open CRATE know how it scales and
crackles when lump is placed on hot
fire. The surface expands more rapidly
| than the interior, and the small frag-
ments snap and fly. So when meteoric
globe with a temperature OF 236 degrees
below zero plunges through our atmos-
| phere with velocity OF from 10 to 30
miles per second, the condemnation of
air in front of it and the friction OF air
escaping past it p.oduce friction sui
ficient to fuse the metal if it be iron, or
| to vitrify the surface If it be OF stony
composition. Large. fattish, or wedge
shaped scales will then be thrown off,
accompanied by loud detonations, which
can be heard for many miles.
Though millions OF small meteors
enter our atmosphere, and thousands OF
larger ones pass across segment OF 1t
and become momentsrily luminous, the
fall of meteoric stone large enough to be
handled, examined and analysed is a
very rare occurrence. Less than ono
thousand observed falls of stone have
thus far been recorded by scientists,
though some single falls have embraced
hundreds OF stones, that at L'Aigle,
France, in 1903, numbering upwsr DIS of
5000 individual specimens.
But though the number OF observe d
falls is less than 1000 We have reason to
suppose that the number OF meteorites
which have come to us from space in
the recent and remote past is very great.
1t is even possible that the earth has
received large acceHsions to her bulk
from that source.
The three principal collections of
meteorites in America are those of Har-
ward university. Yale university and the
Smithsonian institution. The principal
ones in Europe are in London. Vienna
and Paris, and rank in Importance in
the order named. / have examined
three of these collections, namely Har-
ward, the most extensive in this coun-
try; that in the British museum of ma
tural history, the finest in the world,
numbering 442 specimens in 1888; and
that in the museum of natural history
located in the Jardin des Plantes in