Mississippi Democrat. (Carrollton, Miss.) 1844-18??, 1845-01-22
MtsreIIaMp.
DIR. LARDNER's LECTURES.
THE COMETS.

DR.. Lardner introduced his subject with
few remarks on the character Of the
planets, with the view Of subsequent COM
parson with the motion Of comets. He
adverted to the circular orbit of the plan
els, and the fact that that orbit was upon
an inyariable plane, from which there was
no deviation, and thus they maintained a
uniform position with regard to the sun.
The comets also revolve round the sun,
said the lecturer, and this revolution is
attributable entirely to the power Of the
suns attraction In this respect, they
agree with the planets, and thus establish
the fact that they belong 10 The solar sys-
lem. Butin every other respect they diff
fer. In the first place, they do notrevolve
in circles; their path is oblong, or what is
Familiarity called an oval, and the position
of the sun, instead Of being in the centre,
its relative position to the orbit Of the
planets, is at one end Of the oval path OF
The comets. Thus we have the evidence
that the comet is at various times at very
different distances from the sun, being
sometimes more remote than any planet
in our system, and at others in the inme-
diate vicinity Of the sun, indeed there
have been instances in which the comet
has come into actual contact with the sun
--grazed the surface Of the sun, so TO
speak, as was in fact tho case with the
comet Of March, 1Sl3-lust year. The
planets we have seen move in the same
undertaking plane, which may be indica-
ted by the motion Of the hands Of watch
Such is moi the case with the comets.--
They move in every conceivable angle
with the plane Of the ecliptc; some NOV
ing directly perpendicular with il, others
at an angle OF 45e, and indeed at every
possible angle Of the scale; it has also
been demonstrated that there are exactly
an equal number moving al one angle that
there are at another 4 thus the same num-
Der move at an angle Of 400 that have an
angle of 45o, and so on. Their motion
is also irregular in another important par
ticular they have by no means the uni-
form direct or forward motion Of the plan
cts; some move forward and some have a
backward--or as il is scientifically called
IA retrogade motion, and Arrago has de-
termined that the number Of those which
move backwards is precisely equal 10 those
which move forwards. In short, these bo-
dies exhibit the most sovereign contempt
for all the known laws Of motion, or ra-
Their in their motion obscure the letter Of
the law. but hold in utter contempt the
spirit Of il. With another alInsion 10 Ar
rago, DR.. Lardner paid high tribute to
his talents, assidnily, and the omincntly
successful and gratifying resnli of bis la
bors. Arrago, said Tho lecturer, has nsti-
iuled an ingenious investigation with re-
gard 70 the number Of comets. He asks
tie question, how many are probably at
,achcd TO our aysteml II we imagine a
space described BY the orbit Of Mercury,
which i the planet nearest 10 the sun, and
another distinct iheFe15m lying between
The orbp of Mercury and tho orbit az
iler'chel tho remo,onl planet Of ong sys-
lem. Ne shall end upon tho measurement
Of each space. that The proportion Of that
inclui-i willin he orbit az Mercury,
bears proposition 70 the npacn wiihons
dat oSbii and vilhin he ofbl, on llerschpl.
including Of epnfse The whole lnscrmcii'
ale space occupied by ~ The oihcg plansls.
A. - I2A000 Nov he comsls range
htosghous Vie syaiori pretty unilpruly.
being dialgibalsd appsrenlly equally 10
every pant And 90 every rinao come,
hsfelose With has a. aerlAcllon 10 Mar