New-York tribune. [volume] (New-York [N.Y.]) 1841-1842, 1841-12-28

steadily fixed upon the wax for short rime, look
beside It and YOU will see stick Of blue wax as
distinstly as YOU perceive the real wax. In tniS
wav succession OF s7ectra may be Produced
Thus By looking steadily a; red wafer tor q short
tine rou will be able to beside II the ghost OF
.lue wafer; and conversely blue wa:cr will
give birth 10 The ghost Of red one-rhcse two
ca-1rs beng -1rrelative 20 each other thc retu-.
1y he sc.i9a OF the one Is put INTO state OF
no-bii Vibration by which the effect is produced
lis explica5.e by :uPPosiug that when the Fet'na
j, ~, INTO state OF pulsa;ioa lie MOTORS continue
Tor short e iust AZ i bell continues 10 ring for
some seconds after it i struck There are soIae
Instructive and amusing TOYS constructed on this
principle which IL may be well TO mention. here
"a a certain toy which EXHIBITS this around q
crle OF card, having their feet n such positions
- would be- sgcce-sively assumed y two persons
waiting. a-c two figures - arranged tia; wnsa
ono position s. presented by turning the card
-rouad i.ttie thc ncxris exhibited. Afer passing
COMPLETELY round ms frs. position again shown.
the hs-res having TEads comPlete revolution
Now if l0oki1g Though small a5erture pin
hole through piece OF paper, so that only one
attitude Of the iEures can DC seen a. time and
the toy be thsn turned swiftly about, to your eys
viii be exhibited the appearance OF two persons
Waiting. JUS, as they would in tue resi- watt The
explanation i simple wnen YOU iooN a the hTst
position the vibrations caused upon the letns are
continued for the extremely small position Of
tune until The next position comes into view, aud
so far all the rest 50 that he impression pro-
duced is thai Of come Ell series of position; re-
,embing those of the waltz. Thi; This Is the true
explanation !, made eviden; by the fact that II the
card be turned 700 swiftly nething bui confused
impression /, produced and if TOO slowly there
viii bs i. impression OF an irregular motion.
It i mentioned IN the Programme Of this lee
tlcc thar the resemblance between the natural or
saa> and artificial instruments would he explained
bat have only ti1ic to aude briefly that OF the
.ye AID ,he telescope. The eye. as you know. Is
compound LEM, when visible object i placed be.
t0rc IT, rs image is produced or the hinder pant o!
the interior chamber Of the eye. Now similar
contrvance is employed IN the telescope The ob-
Iect-glas, in this instrument corresponds to the
crystalline lens in the csc. made OF glass and in
Tie double convex form. In the eve. when an OBJ
ac, S placed before it, the rays et light are con
yeyed 10 a focus. when q mall image i produced;
and the same Thing i, accomplished in the ;elc>-
cope. 1t YOU imagine that when you view an ob-
s-t through the telescope you the real object,
YOU greatly mistaken; i. not the object it>cii
but only picture OF il, in such position as 10 en-
able YOU To apply to it microscope. This picture
is but one Or two inches from the eye nnd you ara
IT, deal with it, in applying the microscope Just
/ you would with bit OF animal fibre, any other
small object that you wished TO examine. Thus
the telescope is nothing more than device for OBJ
tanning a small picture, near at hand, OF distant
object 80 that the powers OF the microscope may
be applied TO it. The microscope is nothing but
the eye glass near which is the picture. Thus it
Is not the object Itself but only magnifed picture
/ =, b, no rcis fhest
observations conclude this branch of the lecture.
TEMPORARY STARS, &c.
Among the extraordinary phenomena which the
heavens from time to time present, there none
more Observation-Disclosures which surround as
tronomers with more wonder and perpeXity, than
the appearance of temporary stars. Indeed the
views which such appearances open the mind,
# the economy of the universe, are most eXtraor-
dinary From time TO Tine phenomena like this
have been exhibited "a star makes its appearance
in point OF the heavens where none has ever been
seen before, and OF il magnitude and splendor far
superior to those of the stars by which 1t Is sur
| rounded. Ii continues visible for time, sradu
aly declines in splcador finally disappears and is
never seen again In the year 369 there was an
appearance OF this kind, but in 1872 there was
mach more remarkable. y star appeared sud
icnly, that in half hour from iJs first becoming
Visible 1t had reached size equal 10 that Of rtsr
Of the first magnitude. An astronomer OF that day
observing the same portion OF he heavens, and
saw nothing Notwithstanding which was not
perfectly iamliar He retired 10 his dwelling AID
i'll few moments some peasants ran IN and aston
ishcd him by saving that star had baSed out and
suddenly assumed the splendor of star of the hrst
magnitude. He went out and found that it
20 it exceeded Jupiter in splendor, and was for
long While bright that it could be in the
day, in the Immediate presence Of the sun. 1t
continued thus for about two years, when it dsap
peared, and has never since been visible. There
are several instances not quite remarkable
this, which have occurred in similar way. What
purposes these sUbserve III Heavens high
economy-whcther they be called into being
by the Maker OF the Universe, and permitted for
time to exist until they shall have fulfilled the Pur
poses of His wisdom, is -ny mater of cOuIrc-
turc. The fact of their appearance is snques;ion
able: the witnesses have been scientific men, and
their number is SO great to preclude all doubt
Beyond this we are entirely ignorant What
have told YOU, Science tells, and more. The
facts all before you.
The appearance OF periodical stars is also very
extraordinary They are subectio great variation
in their apparent spcad r-heins at first of small
magnitude gradually, after the lapse OF time, in
crcasing in ,pendor that of a star of sometimes
the first and at others of the second magnitude
they then decline in size. and soon become invisi-
be But by watching the spot where they were
seen, after lapse of tune. they will be seen to re
appear, Increase in brightness, then decline and
again disappear Tor another perird. Their recur
is observed 70 be periodical. OF course when
PIE aomenon OF thi, kind IS Observed to occur at
regular intervals, Il variety Of theories will be sus
sested 10 account FOR it; and astronomers accord
ingly have devised several hyPolhe-e, whereby Ia
explain it. Ono of the most plausible Is that de-
rived from the existence Of SPOT. upon the suns