The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1900-11-11
THAT NEIt(jRIC SHOWER
AsTRoN oFsERs WONDERING If THE
ONE DUE LAST YEAR WILL
COME THIS
NoVEMBER's USUAL DISPLAY
What the LeOnids Are Actually Like
Some Showers of Former
Years-PhOtOGraphi
Shooting Stars.


ial 1.-The most interesting astronomical
Question just now Is whether the great
neteoric shower which was due in No
Vember Of last year, but which did not
then appear, much to the disappointment
of astronomers. all over the world, is
to be given up as lost, or whether it
has merely been delayed a year beyond
the calculated time, and will take place
in its full glory next week. The atti-
tude of the Harvard college observa-
tory in this matter is probably TYPICAL OF
that taken at most astronomical stations.
While admitting that the chances Of the
shower appearing are less than a year
ago, Professor Pickering and his assist
ants have not by any means given up
hope, and though the preparations which
have been made for recording it are less
extensive than they were last Novem-
Der, rthey are. still sufficient to take full
advantage OF the situation in case the
Shower occurs.
The November shooting stars are, of
course, recognized institution, and are
due on the 18th and 18th of the month
each year. They are known as the Leo
nids, from the position of their central
point in the constellation OF the Lion,
end the number seen IN ordinary years
would range from fifty or 100 to SOO or
1908. The Harvard observatory noted
some S00 for example, last November.
But what was expected last year, and g
hoped for next Tuesday night, Is a
recurrence Of the magnificent displays
which were seen in 1899, 1888 and 1855,
when not hundrers but thousands and
tens of thousands shot into the earth's
atmosphere. In 1888 a competent observ-
er in Boston calculated that the number
had amounted to 100000 seeming to the
eye to fall as thickly as the flakes IN
H. how
such display would rank with total
eclipse of the sun as the most spectacu-
lar of the celestial phenomena.
The interval between these great me-
teoric showers, as may be noted from the
dates just given, IS thirty-three years.
But the nature of the shooting stars is
such that they are peculiarly liable to
perturbations. so called. caused by the
attractions Of the planets. Within the
last 1900 years, indeed, they have been
swung out of one orbit and into an
other by the influence of the planet
Uranus. During the last period of thirty
three years, it. seems, they have been
especially liable to perturha ton, md
some Astronomers who look for the great
shosyensto "a lSes place next week, as
sriheStAe defas sto this cause.
Z 1t is necessary to understand the Leo
nids' asia stream Of small particles, no
larger 8han grains of sand-the debris,
perhaE1Ss of a eemet-fowing continuous
ly trlsaSni hty. orbit, which annually, in
the middle of November. -intersects the
orbit of the earth. Through most of the
length of this belt the particles are only
sparsely scattered, but in one place they
are cOngregated in a vast swarm, with
relation TO which the others may be re-
garded only as stragglers. The Leonids
complete their orbit in thrty-three
years, time. and once in thirty-three years
therefore. when we enter the part Of the
great swarm, We may look for such a
display as that Of 1888 or 1866. In other
years we see merely the "stragglers." In
time, discourse, Sthe particles will be scat
tered more evenly through their orbit
since the outer ones take more time
to complete the circuit than the inner
ones and tend constantly to fall behind
In the races But this is a matter of mil.
lions of years, like so many other opera
tons in astronomy.
In passing through the orbit Of the
Leonids we see only the particles which
are ignited by entering the earth's at
mosphere, some 100 or 200 miles distant.
No Leonid was ever known to reach the
earth. the terrific heat to which they are
Subjected burning them out before they
have app 6ached nearer than fifty or six
y1y miles, They are to be distinguished
entirely from the sporadic meteorites
which from time to- time appear as fire.
the earth before they are burnt out III
masses weighing thousands OF pounds. A
shower of such as these would be disas-
trous. while the Leonids are quite harm
less.
In the 1888 shower one observer nkened
the appearance of the sky to a vast UNI
brella. This was due to the fact that all
the Leonids, seeming at first to be dart.
Ing in every direction in the heavens, "a
dated from certain fixed center, the So
called radiant, alluded to before as being
IN the constellation Leo. AS a matter Of
fact the course of the Leonids in the
Sky is parallel, and the appearance of
radiation IS due to perspective as in
1.-the parallel lines Of a railroad track,
which seem like the Leonids 10 originate
In single point The radiant, no Yey-er.
is only approximately fixed; and it is an
Important point therefore to establish it
more exactly, since, from the position
of the radiant, astronomers are able TO
calculate the direction in which the Le-
onids are moving. Photography, 1t is
hoped, viii do a great deal to settle this
point Photographs taken with the Har-
ward instruments, both here IN Earn
bridge and at Arequipa, Peru. have very
satisfactorily recorded casual meteors
crossing the field Of vision On ono in
particular, where three shooting Stare
of single system had been recorded n
was observed how exactly the point of
radiation could be defined by the conyerg-
ence Of the three paths, especially In com
parison with visual observation of the
three meteors which was fortunatnl
made at the same time If next Tues5ay :,
the. great swarm reappears, therefore
and IT the wea Their conditions are favora,
Die the Harvard observatory hopes to Sc
iscure on its Photographic plates comn:ate
data Tor determining the radiant. and con-