New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1883-01-24
TIE LECTURE.


h, VIII trv 70 give YOU some OF idea Of the
ystem TO which earth belongs and OF which the sun
Is the ruler. Any person watching the sky even Tor
abort time will his attention called almost hume
dately TO few very bright stars. II we 80 out TINS
evening and look up towards tho south We shall nnd the
BRIGHTEST star ia not very far from the MERRIAM, and
shall notice ar It another bright stor belonging to the
planetary system. These stars. find. continually
moving and that Is what has given them ther name OF
panets-the wanderers II was early observed Oy the
ancents that there five SIX bodies In the SKY
that were ell the time in notion and while the other
stars preserved their position and confSurauon from
daY to day. from year TO year, and from age TO age,
these arc continually changing teir places. The stars
hat compose the DpPer look tonight almost
precisely they did 1000 years ago.
So It is with the constellation Of Orion But these
brightest OF all the have been ohang their places
continually The ancients names 10 those known
"a planets The one nearest to the was called Mer
eury-perhaps you it last night or tho night before
The next was called Venus the brightest OF all tle
group who sgnazed her transit across the face OF the
sun a few weeks ago Then came Mars.
then JuDier end then Saturn. constituting the
five planets TO the ancients. About 100 years
ago the elder Hersce added more 70 the system OF
planets-the time had been discovered in the
history Of the world Up to that time there had been no
discoveries OF planet hut Hersshe added to the group
Uranus and 1916 still another-Neptnne (which is as
yet the outside OF the systeml-was added oY
IN most remarkable feat Of astronomical mathematics
on record-even before It was seen
Those bodies along with the Earth which COpernicus
about the beginning of the sixteenth century showed 10
be q body revolving around the SUM- constitute
the main portion OF Our planetary system. and
ali of them move around the sun in paths pretty
nearly circular and pretty nearly on one
level. And then between the planet Mara and the
planet Jupiter there is for Others and there Is &C
tually group Of 224 225 asteroids az present known
smaller bodies known minor planets, which are per
ID.
haps the material Of another planet spoiled in the
msking-I don't know which. Then be-
sides these bodies l have named. al
except Mercury have and satellites OF
their the Earth having one Mars twcJupiter four
Saturn eigls. Uranus four and Neptune one, making
satellite family O. twenty.
These constitute the plane system. ano ~ may nc
separated into classes Humboldt grouped
them-the terrestrial planets resembling the Earth very
much, and the major planets Mercury, Venus, the
Earth and Mars which belong TO the terrestrial class
vary IN diameter from 5000 to 5000 miles neither
VARYING very much in density from the Earth The
smallest weighs about one-eiehb much az the Earth
AID rotate their IN pretty much the same time
within twenty-three twentvfoIr and a half hours
Then comes the gap nterspersed here and thore with
the minor planets have spoken or and beyond come
the major planets. the great bodies OF the sysem
first Jupiter nearly eleven tines the diameter o! the
Earthani consequently nearly thousand times ne bulky
aud nearly SEQ times hea7y-almost snn Of itself;
then Saturn then Uranus aud then NeprnethOse four
resembling each other IN much the same way IS the
terrestrial planets resemble each other.
THE ORBITS OF THE PLANETS.
Now as To the motions OF bodies you may figure
70 yourselves thoir orbits they called the paths
In which they move. as being material wiles passing
nearly Giro arly. which the planets
may be regarded IA sliding bodies.
You must think of those orbits not exactly fixed in
position or in magnitude. but all the time disturbed, La
bic 10 be swayed little one way or the other, pulled
around out Of shape ono way and squeezed up I'm an
other changing slightly by the action Of the bodies
upon each other These orbita very nearly, said
before circusr nearly that even If the most &c
centric OF them thrown the screen you would
hardly notice that II not circular Mercury is the
most eccentric Of them all We should fad that the
difference between the longest diameter and the short st
"a about FIVE six inches. The would at
however that the not IN tne centre you would
fad that il at side Instead of being circles 10
speak more accurately they ore epses or oEal-, as
Keper discovered. The ATistotcian and pr0t philos
opheIs argued that etIes ~ani3i o. perez
ton aud that oval bodies coul3 not move III perfect
curves. there great TeyuOn Of feeling when he
announced that the orbits inste OF beng circular
Of the sun. You know before the time OF Kepcr II
supposed that the Earth the centre OF notion but
ton OF the planetary system We have since discovered
that IL rapidly through space very rapidly prob
ably somewhere from ten to thirty miles sccondwc
IT. II follows If look do wn upon the
body distance should It moving most In
an orbit sefreturnng not Ia path that comes around
10 the same place again going through space
in a uork-screw spiral manner The san travels |
OIL III all oblque direction while the planets move
around It, some have Thought IT necessary, |
asrononyi that II faulty ri the bottom If the
the centre-pot understanding tue doctrine OF
tho 1estiyity OF notion The Iac Is hat any n9uon OF
tie CT the systen does not 10 hs slightest Affect
the reatiys motion OF the bodies Of the sysem We
WhiTing around uDon tho surface OF tne earth at an
enormous rasSomethine over thousand feet second
but IL does not affect eur POson In reference u each
otter II move ny hand around me- BOldiug ths book
II IL perfectly proper 20 that the book 10 moving
tancs from ao that moving aud
tho building IL you'd not APPEAR 10 be moving IN circle
should foferrsG to this IL was not for the
fact thai there Is gentleman IN Germany WHO
Is publishing series OF ggT o1e eseiy rev
Move Not" and srguing-as SAID moment sso-that
tie COpsrncian system IA upset by recent
discoveries and have foaad some such people In the
United states.
Lie natural enough 70 ask How come these bodies 20
in ORBITS Ike These and what Keeps then moving
and educated hall educated man Is very apt 10
conceive niI1 self that there II cOnlrYance In
universe by wbeh the planets attached 10 the
aud driven forward Ia their paths or that the snn
carries the psneis with IT, az CHIPS 19at upon the sur
face Uf lake They do not UNDERTAKE. az keper ana
You viii grant gravitafion - the first law
motiOnto keep them Ia their orbits IL to DC let alone
will fall to TIE gfounc, and that all bodies VIII act IN
corresponding WAY Dut gran. thst, ana Iounng rs
stop them. Why should they stOpl The Earth IL whFl
ing and there is no need Of propulsiye force 20
occur without tho application OF some force |
aud II bodies moving tley wi except 10y the appli
lines. II they are held 10y attraction toward central
body, they will circle around IN paths |
which are Insthe aoafiealy established by INC
sections, and they have H. need OF |
locomotive boiler o engine 10 Keep them going |
have put Ia Oh You will grant eraVitatou. 10
understand me all saying that there Is no mys
terry planets motions. There rs Just Ihe one
snge OBSERVATION-DISCLOSURES ~ ls very prOIeunu
one. How Is that an atom Of matter can attract
another matter bow great the distance no mat
Yer What intervening substances there may DC now
VIII acc upon It, least behave as n IL acten upou
DO NOT know; cannot tell Whether they are pushed
together. by means OF intervening ether, or what
- the action, Icannot understand. IL stands Win me
aong with Tie TACT when VIII that nay arm snal
tlse II rses II is inserutae All the explanations That
nave been given Of IL merely darken c0ni
sci With words and understanding They DO |