National Republican., 1873-11-10
THE CELESTIAL WORLD.
Columbinn University Course-I.ccturc by
profs ssor Newrotuh

| The opening lecture Of the course OF twelve
| on the history and science OF astronomy, before
the students OF the Columbian University, and
such others as may please to attend, was delly-
cred on Saturday evening, at the medical col
lege Of the university, II street, between ThIr-
teenth and Fourteenth streets, by Professor
simon Newcomb, Of the United States Naval
A large aud sppreclatIve audience was In at
tendance, and listened with deep interest to the
| very able and Instructive lecture.
Professor Newcomb Is the author Of the
leaned and Interesting article Of, the "Mnnster
Telescope" which originally appeared Ia ''Scrib-
ners Monthly."a synop1is OF witch wa, gwen
In the REPUBLICAN OF the 2Ith ultimo.
TIE LECTURE.
The lecturer began by stating that Il was pro-
posed 10 treat the subject historically, because
the order OF historical development would be
the natural order OF presentation. lie therefore
passed rapidly In review the astronomy Of an
Client China and Hind50stan. lie narrated the
history OF "Ili" and "iIo," astronomers royal to
an ancient emperor Of China, twenty-five ccniu-
rles before the Christian era, who were summa-
predict an eclipse. but the astronomy, bnth OF
China aud India, Is no mixed with fable that we
can learn little more OF 1t than that It shows that
even In those ancient times men had some faint
Idea OF astronomy. live seek for The
COMMENCEMENT or OUR ASTRONOMY,
we hnh It not In China, but on the plains Of
Baby lon, among the Chaldean shepherds. The
nrst discovery TO which We can give the name Of
astIonnmical science Is that OF the annual mo-
tion of the sun among the stars. The stars rise
and set 3G5 times In 355 days. aud the lecturer
Illustrated by diagrams how this proceeded from
the annual revolution OF the sun around the ce-
les,ial sphere.
We now know that this apparent revolution ia
really the revolution OF the earth around the
sun, and the appearance Ia the same ~ II the
sun moved around the earth. u the stars were
visible IN the day time we should see the sun
surrounded by and moving among them at the
rate OF ABOUT two OF his damcters in a day,
which motion carries him around the whole cir
cult OF the heavens In year. Tho path OF the
sun among the stars was called
IRE ZODIAC,
and commencing at the yernal equiuox, 1t was
divided into twelve equal divisions known as ihe
signs OF the zodiac. In the nrst six signs
anI Ssn, miSn IN wy sun passes between March
the days are longer than the nights. September
y ne crosses the equator towards the south, and
InTlng thg remaining hali OF his course the
nights are longer than the days.
Inc next great step In astronomical science
was made by lipparcus OF Rhodes, who Hour
snea @ u. {; leo, and VINO has been honored In all
ages as the father Of astronomy. One OF his
great works was the preparation Of the
FIRST COMPLETE CATALOGUE or STARS.
which he Ia said to have prepared In order to en-.
able posterity TO determine whether any change
would lake place IN the starry heavens. THIS
catalogue stu exists, and though the errors fire.
quently amount to q dozen or more all the stars
IN II can still he Identified. lie was also the dis
coveter OF the procession OF the eaulnoxes
which was shown by the fact that the sun
crossed the equator annually little sooner than
y made complete revolution among the stars.
Ihe sun returns TO the same equinox In eleven
minutes less than three hundred and sixty. i've
Gays slx hours, while 1t requires little more
than this time 70 return to the same star,
Hipparcus also discovered tho Inequalities In
the :"
MOTIONS OF THE suS AND NOON
which we now know TO anse from the eccen.
tricities OF their orbits. lie found that the sun
required eight days more to pass through the
nrst half or It's orbit from the yernal 10 the
antuInnal equinox than 1t did to pass through
brafed theory OF the eccentric by which the
earth was placed, not In the centre Of the sums
orblt, but about one thirtietn OF the way 10.
ward the circumference. These theories OF lhe
suns molions were elaborated by PtOlemy, who
was supposed to have propounded the ceie-
bIateI IheOfy 81 the motions OF the planets In
eplcycles. on this theory the planets are sup
posed 10 move on the circumference OF small
circles, whose centres are carried around ihe
earth on other large circles.
The lecturer showed by q diagram how this
double motion resulted In q planet forming
series OF loups. The apparent motions OF the
planets are thus well represented, the annual
motion OF the earth around the same beinp, as IL
were, transferred to the planet itself Ia an opDo
site direction. This theory, known as the Pole
my system OF the world, was almost universally
received Tor fourteen centuries, when IL was
supplantei by that OF C0pernicus.
Upon the conclusion Of his very interestIny
lecture, Pr0f. Newc0mb announced that the
next lecture OF the course would he delivered an
Fnuay evening, NJ the same place, Oh the Meaa
urement OF Time and the Formation and IIlstory
OF the Calendar.