Evening star. [volume] (Washington, D.C.) 1854-1972, 1890-04-21
NiETEORS AND COMETS.
Prof. Searle Gives an Interesting Talk
About Shooting Stars.

ABOUT shooting STARS
Prof. George NJ. Searle, in his lecture at the
| Catholic University on meteors and their rela-
ton to comets, stated many interesting astro-
nomical facts. He began by making some re-
marks regarding the frequency of ordinary
meteors and especially their greater frequency
toward morning, because at that time we are,
as it we're, on the bow of the earth, while IN
the evening we are at its stern. 1t is estimated
that over ten million meteors fall on the earth
in the course of the day visible to the naked
eye-that is thirty to sixty an hour-on an
average, at any one place. Observations have
shown that meteors travel with immense We
locities They are usually as much as fifty
miles away from us and, indeed fifty miles
above the surface of the earth; which shows
that the atmosphere is higher than has been
commonly believed, for they derive their heat
and light from combustion caused by their
contact with the atmosphere. A meteor has
been observed to come from the Pacific to the
Atlantic in about two minutes-that is at a rate
of about twenty miles second, and that was
not at ali unusual velocity. 1t is evident
then, that meteors are really planets, but
most of them are very minute As they can
not be seen to reach the earth their size is es-
timated by the light they give. Twelve foot
pounds OF energy is equal to the light of a
standard candle. On this basis the weight of
common shooting stars has been found TO vary
from one grain to one hundred grains There
being about fifteen million grains in a ton it is
possible that ten tons may fall ON the earth in
day, but even II a hundred tons should fall
every day it would, it is estimated, only make
layer one inch thick III a thousand million
years. OF course there are some larger ones
called aeroltes and these have been known to
fall to the ground in considerable numbers,
but the largest ones actually reaching the
earth have not weighed over 500 pounds,
though they probably weighed more when
they entered the air.
IErEoRIC SHOWERS.
Meteors have been seen to fall in showers at
various times Perhaps the most remarkable
IN this century was one of November u, 1868,
III which $50. coo were counted by an observer
at Boston in the space of six hours. These me-
teors seemed to diverge from a single point in
the sky and this Is always the case in displays
of this kind. AS one old lady remarked. the
sky appeared like big umbrella. This is the
effect OF celestial perspective and mere means
that the meteors are all travelling in parallel
lines. This display was found to have occurred
previously in 1893 and was traced, when atten-
ton had been called to the subject as far back
as the year 9o2, appearing at intervals of about
thlrty-three years, there being records of a
large number OF its occurrences since that date.
1t was found that they could be accounted for
OHiy ny d SWARM OF lneLSOrS travelling IN an
ORBIT around the sun, requiring thirty-three
years for Its complete circuit and the pro-
cesslon or swarm being SO long as to require
two or three years to pass a given point. On
the strength OF this conclusion Prof. Newcomb
predicted a repetition of this shower i'll 1866,
which was observed with repetitons i'll 1867
and 156s, all being quite remarkable. though
not SO noticeable as that OF 1888
The next step IN the matter was the dis
coyery that the comet of 1866 moved in the
same orbit as these meteors and that the
slighter showers which occur in August of
every year move in the same orbit as the comet
of 1862.
COMET RETIRED FROM BUSINESS.
The lecturer then proceeded to give an &C
count of the remarkable adventures of Biela's
comet. This comet was discovered early in the
century and found to move in six-year orbit,
and was SO observed during several returns.
In 1916 it was found 70 have separated into tw o
comets, travelling side by side. In 1882 the
double comet was again seen to return. In 1859
circumstances being unfavorable. it was hardly
expected to be seen, but in 1865. though care
fully looked for, no trace of 1t WIS found. Now
the orbit of this comet Intersects that OF the
earth, the junction being about at the point
which We occupy III the end of November, and
in fact, 1t had been feared that collision
might occur between Biela's comet and the
earth ever since the time that its orbit had
first been calculated. In 1872 as VIC crossed
this point, shower of motors was actually
observed coming in the same direction and
following the same course as the comet itself
would have done had it been there. SO con-
hdent was the astronomer Klinkerfues that we
had actually collided with the comet itself that
he sent to PogsOn, at Madras. the following
telegram. probably the most remarkable that
ever crossed wire: "Biela touched EARTH
November q. Search near Theta Centauri -
Search being made. a comet was actually
found near that point, but bad weather pre-
vented sufficient observations to determine its
orbit. 1t does not appear probable that it
was the principal body of the former comet
as it was not on the right part of its orbit, the
comet should have been gone by some con-
siderable time earlier. but that there is little
doubt that this comet forms part of the same
system. and indeed it is moro than doubtful if
Bielas comet, as such. any longer exists The
probability is that the whole thing has been
broken up into a meteoric stream Besides
those mentioned. other meteoric streams are
known to be accompanied by comets, moving
In the same orbit and II appears probable that
all OF the meteoric streams or showers occur
ring periodically the remains of comets
which have been disintegrated by planetary
perturbations.