The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1903-11-13
The SKIES in NOVEMBER
POSITION OF THE MOON AND PLAN
ETs DURING MONTH.
The Great Solar System and the Plan
cts Whirling Around 1t mt Won
derful Velocity.
Baltimore Sun.

w VII Ou III olus last qudAtc Oh Nh~
18th. new on the 18th and first quarter on the
9th. Or the 10th she will be in perigee and
on the 18th in apogee. While on the LIST OF
the month the sun is about IA degrees south
Of the equator, he will be more than q de-
grees distant from it on the last. The planet
Mercury will for a short time be In Virgo,
but during the greater portion of the month
in Scorpio. Venus will be in Leo during the
whole extent Of November. and act as a
morning star. Since 1t rises about
3 o'clock and the nights considerably In
crease in length, this beautiful planet will
be visible for a considerable length of time
to any early riser who considers it worth
his while to devote some time occasionally
TO the contemplation of the splendor Of the
celectial map spread above him. Mars is in
Sagittarius. This planet sets between Z
and S o'clock In the evening. Jupiter is still
in Aquarius and Saturn In Capricornus, the
former setting at nearly / o'clock in the
morning, the latter between 8 and 10 in the
evening.
The distances of the planets from the
great luminary around which they are
whirled by virtue Of the enormous force of
attraction it exercises over them are all
based upon the so-called astronomical unit,
by which is understood the distance OF the
earth from the sun. This distance. as a
noted writer on astronomy felicitously ex-
pressed it. is the great fundamenta datum
Of astronomy, the unit Of space, any error
in the estimation of which is multiplied
and repeated In a thousand different ways,
both in the planetary and sidereal systems.
A brief sketch of the history of the deter
mination or this great unit-a problem
called by a noted English astronomer 1.-THE
noblest problem In astronomy"-certainly
cannot be regarded as deviod of interest.
The student conversant with the elements
of that extremely useful branch Of mathe.
matics called trigonometry knows that.
were the angle known which subtends the
radius of the earth as viewed from the sun
angle called the solar p~arallax-the
problem would be an extremely easy one
Nay, even one not acquainted with the
principles of trigonometry could easily un-
derstand by q simple construction how
easy OF solution the problem OF the deter
mination of the suns distance would be,
were the parallectic angle known. But in
this determination Of this minute angle
lies the difficulty of a problem to the solu-
ton of which SO many gifted men have
consecrated their noble efforts. Measuring
this angle amounts to the same difficulty
as the measuring Of the angle a cent would
at a a - issoiC tidh itail a
mile. If we knew the distance of one
single planet from the earth exactly We
could, by a simple application of Kepler's
Third Law, determine the suns distance at
once. But, to quote a noted writer. In that
word exactly are hidden great snares
and pitfalls"
THE TRANSIT OF VENUS.
AS to determining the distance of Venus
from the earth, from which the distance Of
the earth from the sun would follow at
once, the astronomers Of the eighteenth
century were full Of hope and zeal. In
this expectation they seemed justified by
their knowledge of the calculated times Of
the crossing of the planet Venus across the
suns disk. They confidently expected to
attain something like a permanent settle
ment of the statistics of our system, but
they were grievously disappointed. The
uncertainty as to the suns distance, which
they had counted upon reducing to a few
hundred thousand miles. remained at many
by combining the results for both transits
of Venus over the disk of the sun In the
years 1761 and 1769, published a value of
the suns parallax in 1924. which would
make the suns distance a little over 95.-
100000 miles, by far the most accurate
value obtained up to that time, except the
one furnished previously by the great
French mathematician and astronomer La
place, who had based his calculation upon
an entirely different method of treatment,
viz, that of the lunar parallectic Unequal
two men of unq1estionable genius~the one
result derived from the trig0nometrical,
the other from the gravitational method
could not but create great confidence in
ever, vas materially shaken in 1854 by
Hansen, and, four years later, by Lever
rier. so famous in the history of the dis
on Dec. s, 1874. was eagerly looked FORWARD
to by the astronomers of America, Eng
land. France and Germany. The eventful
day had no sooner passed than kilograms
poured In announcing an outcome or con-
Siderable, though not of unqualified success.
The weather had proved generally favora-
BILE; the manifold arrangements had worked
been secured, and a store of materials had
been laid up, of which IL would take years
10 work out the full results by calculation.
But it was found that unanimity was as
remote as ever.
A certain formidable phenomenon, known
as the BLACK Drop" stood I'm the way of
attaining rigid accuracy. Already in the
l761 and 1869 1t had been noticed that the
planet at the time of internal contact with
the suns disk showed a "ligament," or
appearance of a round disk, neatly touch
ing the edge of the sun, and the time of
each contact was thus made doubtful by ten
or fifteen seconds. Some astronomers as
~ tiAo oAAAsh "
Instruments imperfections; others TO at
mospheric agitation; others, again, to the
optical encroachment OF light upon dark
ness known as "irradiation." 1t is probable
that all these causes conspired In various
measure to produce It. 1t is true that in
the observation Of the 1874 transit Of We
nus the black drop" gave less trouble than
had been expected, but a new difficulty had
appeared from which there seems to be
absolutely no way Of escape, viz, the fact
that the planets atmosphere caused il to
be surrounded by a luminous ring as it en-
tiers upon the suns disk, and thus renders
the time of the contact uncertain by at
least five or six seconds. In the transit of
1874 and In that of 1852 differences of this
amount continually appeared among the
results Of the best observers.
Other methods have been applied by as
tronomers of different nations, Of whom
Hall deserve special mention. Professor
Hardness. the able successor OF Newcomh
as director of the American Nautical Al
manac, surveyed in 1891, from an eclectic
point of view, the general situation as re-
garded the suns parallax. Convinced that
no single method derived an exclusive
preference, he reached a plausible result
by the mathematical rules of that wonder
full and fertile doctrine known by the name
the results into account and combining
them.
OUR DISTANCE FROM THE SUN.
According to this We may accept %. So
600 miles as the length OF our measuring
rod for space. Nor Is there much hazard
In fixing the comparatively small value OF
100. 200 miles as the outside limit of its