Mississippi Democrat. (Carrollton, Miss.) 1844-18??, 1846-04-15


that IN gain admittance TO the high
er departments of physical science. By
these it is that the heavens are scaled;
these are the Pelion and Ossa on which
Newton and La Place have climbed, TO scan
the vast domain of the Almighty. b.
these have the sun and planets been mea-
sured and weighed-taken 10 the hand as it
were. and their distances and motions ac-
curately determined; By these alone have
we been able to derive our loltiest concep-
tions of the inconceivable vastness Of the
universe, and the still more inconceivable
majesty, sublimity and omnipotence of the
Deity.
The satellites of Jupiter, their discoye-
ry by Calico, and their eclipses were next
considered; the use made Of these eclipseS,
and the remarkable discovery, by means
of The velocity rendered quite inlelli-
gihle to all. HadIey'S labors in endea-
yoring to determine the parallax of the fix
ed stars. were also alluded to, as having
resulted in determining the velocity OF
light. The method of La Place, by ma
thematical equations, was also noticed
A very good explanation of the alteration
of light, the same as that of HerschelI, was
given, which, We presume, was quite in
teligibe. The very singular relation eX-
isting between the mean angular velociues
or mean motions of the three frs satel-
lifes of Jupiter, was explained. This re-
lation is such, that if we add TO twice the
mean angular velocity Of The thrd that of
the first. the sum will be three times that
! of the second. Il is also 4 curious dCduc-
| ton from the same relation. that il from
the mean longitude of the first. added u
| twice that OF the third be subtracted three
times that Of the second, The remainder
! is always the constant quantity of $50 de-
nrees: so that the position Of any tyyO OF
| Them gives that OF the other. Another
curious consequence IL, that all the 81
teIIites cannot he eclpsed al once, though
there is one instance on record, according
to IIerschelI. of Jupiter's satellites being al
! enlinsad IT nnna- Il : rosa--ls-l - si5i y
neux in 1851. It is probably mistake.
/ These eclipscs have heen Of immense va
/ lue to the world IN the determination o.
IIonoitude. though the methods bv lunar dis
Itauces aud iocculiations are o.tener used.
An argument adverse TO The idea OF resist
ing medium, is also derive5! from the
above curious relation subsisting between
the three FIRST satellites.
The beautiful planet Saturn, with as
rings and seven moons came next IN order
OF these satellites we know much les
Than those Of Jupiter. The appearance
of the heavens to an inhahIlant Of SJturI
was beautifully shown with a luminous dI
agram. Prof Mitchell. in speaking a
/ the rinus, observed that BesSelI had SUP
: posed that there might ne three rings; an.
: Father ID Vico, of Rome, six or seven
The idea had also been advanced BY BeS
: sell, that The rings Of Saturn might be OF
: liz a chain of globes following one anothe
: in close succession. 1t IS the OpiniOn Q
! Prof. NJ. that we know but very little Of til
: planet and lis appendages, that II IS vet
terra iRcognitO, opening vast field for 10
: lure lahOrs. The disappearance Of th
= rings of Saturn was mentioned as afford
inc evidence OF the rings not having IN
5 same Uniform thickness throughout. i'h
. rings, when seen with their edge toward
f The observer. assume the appearance Q
e Two dnSae extending from the sides Of Oh
ri planet. Some observations were anal
: about the manner the rings were susiaIne
: about the planet. The solution of til
: question was referred to the theory Of equi
}. librating forces. The centre Of gravit
: of the rings described around the plane
e a very minute orbit. ID is demOnstrable
d thai ii the rings were perfectly circular, c
y equal density throughout, ans exactly con
centric with the planet, they would De In
k stale of unstable equilibrium, which eve
l. The slightest cause would destroy, ar
= thus precipitate the rings upon the plane
r The stability, therefore, Of those wonderfu
II appendages only be found in an uneqlz
j. distribution of the matter composing theu
t. of which the centre of gravity IS no. h
e centre of the rings. The observations
Ie Bessell, il is thought, will lead to some e.
h tirely new views regarding the compile
} :; system OF Saturn, Of which there Is muC
r vel TO be learned The curious phenOm,
I'd ma of the disappearance of the rings ever
a fifteen years, arises from the fact OF lis 4
lie ways remaining parallel to itself IN !
Ell revolution about the sun which revolutIo
ie occupies about 30 years.
he Uranus, the most remote Of the plane
b. YET discovered, occupied few moments
ne The close Of the lecture. When Hersche
I'd discovered this planet, he was long
a. doubt in regard to its nature. lie did
nd fact for some time suppose 1t to be mere
n comet. 1t was not until more than
in year after he first saw it, that he ascertai
sc ed its real nature. Prof. Mitchell exeres
a ed, in regard to this planet, that we we
a as yet quite too ignorant of il to ventu
ic- any definite opinion. He doubted {