The evening times., 1896-08-11


Shooting stars have filled the heavens
for the past week Whether they have
added anything to the intense heat is
matter for the scientist to determine by
careful reckoning.
The books put down August o, 10 and
IL as the dates for the periodic return u
meteor shower every year This year
there was apparently o beginning OF the
shower about last Friday On succeeding
nights there have been unusual numbers
OF meteors Saturday Dight in half an
hour eight OF ten were Observed in the
vicinity of "The Dipper" and nn The other
side OF the pole star in the neighborhood
of 1.-THE Chair OF Cassiopeia.
Last night one OF the most brilliant
displays was to be expected, but the clouds
iDterfered Tonight will probably be
clear and many meteors will he seen
or these interesting bodies Prof. New
comb, of the nautical almanac office, says:
1T is now universally conceded that the
celestial spaces are crowded with iDnumer-
able minute bodies moving around the sun
in every possible kind OF orbit. They may
not average more than one in million
cubic miles, and yet their total number
exceeds all calculation. or the nature Of
minute bodies Of this class nothing certain
is known. Whatever they may be the
earth is constantly encountering them in
its motion around the sun. They are
burned by passing through the upper re-
gioDs OF our atmosphere, and the shooting
star is simply the light OF that burning.
MECHANICAL,THE0R OF HEAT
.'The questions why they are burned and
how they can burn SO suddenly asi ~ith 50
intense heat as TO be visible hundreds Of
miles way were STUN bling blocks In the
way OF investigators till they were an
swered by the discovery of.the mocha nical
theory of heat. 1t isnow established that
heat is only one form OF motion. conse-
quentiy II body moves rapidly throughthe
air, the impact OF air upon it ought to heat
1t just as warm air would, even though the
air itself was cold, This vas proved by an
experiment by Sir william Thomson.
s.The various phenomena of .aerolites,
meteors, shooting stars and Teteoric show
ers depend solely on the number and nature
OF the meteoroides which give rise to them
Ifone OF thesebodies Is solarge nd firm as
to. pass through the atmosphere and reach
the earth without being destroyed by the
potential heat, we have IN aerolite. When
the body first strikes the atmosphere the
resistance becomes SO enormous that the
aerolite is broken to pieces with such vio-
ience that 1t seems to explode. A loud de-
tonation gives further color to this opinion
and the explosion Is spoken OF as the cause
of the detonation. Really there Is good
reason to belieye,that both are due to the
body striking the atmosphere with a We
locity of from 600 to 1000 miles a minute.
''lf the meteoroid is SO small or 60 fus-
ible as to be dissipated In the upper re-
gions of the atmosphere we have a COM
mon shooting star or a meteor of greater
or less brilliancy By an experiment made
by Prof Harkness OF the naval observatory
1t was found that meteors are first seen
at u height of about seventy-five miles and
disappear at..an average height Of fifty
five miles This was based upon a series
OF observations here and at Richmond
There was no positive. evidence that any
meteor Commenced to be visible at
greater height than 100 miles. The OH
servations gave proof that our atmosphere
pruhabiy commences at a height Of 100
to 1i0 miles, instead Of forty five, as
formerly supposed. .r.-a,ps,ss tuv.r.
METEORS TRAVEL IN SwARMS.
Ordinary meteofs, as Seen on an evening.
move in any direction and are seeminly
scattered at random But the case is en-
tirely different With ineteoric showers, such
as are observable at this time. Here is a
swarm of these bodies all moving in the
same direction.
By careful tracing of their paths they
will be found to meet in common point
of the heavens THIS Is called the radiant
point Italways appears at the same place
without reference to the position OF the
observer. The meteors now to be seen as
a meteor shower. appear to radiate from
point in the constellation OF Perseus.
They usually leave behind them trail of
shining dust, and are supposed to be con-
nected in some way with the comet Of L s62,
whose path they seem to follow.
The number observed on single even
ing has never been nearly SO great, SO far
as any record is known. as the number
counted in the same time during the Novem-
ber shower Some that are seen. however.
are very brilliant and well repay the star
gazer for his trouble
The first notable record OF an observa-
ton Of this shower was In 1898. From
data then obtained and on numerous other
occasions the conclusion has been drawn
that both the periodic showers are caused
by some heavenly body that has been
broken into fragments. Also since the
August meteors have been fonud to be
more evenly distributed 1t is thought that
1t is the older OF the two groups OF frag-
ments that are periodically crossed by the