National Republican., 1873-11-18
THE MAGIC OF LIGHT.
LECTURE D. PROP. PEPPER LAST NIGHT
Tho Romance OF Optics-woudcrfsi The
uomenH- Brilliant and Beaus,t-i Illu-


uomen1-Briiilant and Beaus,tul IlIu-
siens.
Despite the severity Of the mingled snow and
rain storm, fair audience greeted Prof. Pepper,
director Of the Royal Polytechnic Institute,
London, at Lincoln hail, last night 10 hear bis
very instructive and interesting lecture on the
"Romance OF Optics, and to witness the bril-
liant and beautiful experiments with which II
was accompanied.
The lecture was given under the auspices OF
the "Star Lecture Association" OF this city, and
was tho nrst OF series OF three brilliantly ilu-
minated lectures on the magic Of light and
sound, the remaining two o. which VIII bc ne-
llvered NJ Lincoln hail on wednesday and FIJI
inc lecturer was ably assisted in his expert.
mcnts by prOf l.. W, TObin. OF London, VINO Is
the inventor Of several celebrated Illusions. On
the platform last night variety OF apparatus
was displayed, and 10 the rear was curtain
eoncealing the "ghcsr paraPhernalia'
THE LECTURE.
The Professor began by acknowledging the
compliment conferred upon him by so large an
Attendance on such u stormy night and thea
prOceytlc,I TO announce his suhjcct-"The Prom-
iocut Chafacteristics aud Properties OF Light
First, he sari, he would show peculiarly Of
nRht known ~
"pERslsTESCE or visioN,"
property by which, under certain conditions,
an image will remain Impressed upon the eye
after Ihc image Itself has been removed. Nn
i,nage was the Impression OF the object upon
the eye, 80 long as u Is within view, ,ectfum
IL the Impression which remains upoL Ne eye
after the object u removed. And nrst, he - ould
present feeble Illustration OF natural light, and
ihe Manner Of Its production, In an endeayor to
answer the question, 'What Is light" lie ac-
cOrdngly ursL showed a long slender Jet Of ig-
nited gas, and afterwards directed Il upon \
piece Of metal which, when snlllcent.y fused,
threw on an eruption OF intensely brilliant
sparks, which fell In shower from the front OF
the platform.
slmiar in character to the process supposed TO
he going on continually. on an immense scalc,on
the surface Of The SUM- the great mass OF the sun
icing metals 10 fused state. lie incidentally
remarked that philosophers attributed the iii-
tense heat Of the summer OF two years ago 10
ihc fact that Just then the sun was "stoked up"
with surplus oi magnesium, which produces
Intense heat.
Itmay be said here that the experiments were
performed with the lights In the body Of the hall
turned down u their lowest point.
ARTIFICIAL LIGHT,
he said, 1, produced by the combustion OF MI
mute particles Of carbon. found In various sub
stances, aud ia illustration he produced q torch
afssuiar, InauagcSbie iiaine, pat lie bowl being
nlled with certain compound, when he Inverted
the torch Il was ignlied aud lofty column OF In
forward from the stage towards the audience
Rejected light was sliudedt6, and the air was
described as universal renectlngnnedum. In
Illustration OF the manner In which light Is re-
nected he exhibited a large cylindrical upright
tank, flicd with water, IN the base Of which
were set small circular plates Of glass, ono on
each side. A strong light being placed behind
tue tank and opposite these openings, the direct
rays were seen 70 stream through the water and
thcn 7, moved the glass plate from the front OF
The tank, allowing the water to spurt out In u
Jet, several feet from the platform, This Jet was
to absorb oil the rays OF light they following
iis curved course, and giving IL the appearance
" stream OF molten metal. The interpositlUn
OF series OF yafiousy colnred glasses between
the light and the water changed the color OF the
Jet tnstantancOusly, producing beautiful effect.
Passing to tue undulatory theory Of light, he de-
scribed
TIE LTnER WHICH PERvADEs ALI srAcE,
aud which by Its fluctuations conveys light. This
undulatIon was illustrated first by a large glass
goblet, against the sides OF which were sur
pended small balls. The drawing OF a violin
bow across the edge OF the goblet caused q vibra-
ton Of the glass, which communicated itself TO
the suspended balls, causing them To dance and
beat u tattoo on the sides OF the goblet. Another
Illustration was.gtvcn by the use Of glass bot
TONED tank, with light underneath aud filed
with water, and the waves produced by the agl-
tatlon OF tne water were beautifully reflected,
In all their cOncentrc fluctuations, upon screen
and upon the ceiling OF the hall. These yibra-
tlOns, he sahl, were feeble aud slow In compar-
lson 10 those Of the luminiferous ether, which
have different velOcitier, thus producing the
d,n' rent colnrs red requiring four hundred mil
lIuns OF millions per second aud yellow requiring
seven hundred millions Of millions.
AS the waves OF the ocean dash against the
rocky shore and wear It down by their ceaseiess
shocks, so these waves OF light strike the optic
nerve, AMI, II frequent and intense enough,
cause temporary or permanent blindness, and
even death itself. At the London Polytechnic
Institute he had killed three sheep by the light
produced by an Immense electric coll The Pro-
fcssor related
THE EXPERIENCE OF SIR ISAAC NEWTON
who, after the experiment OF gazing intently at
the sun and then suddenly looking at a black sur.
face saw long afterwards constantly before him
TO shut himself for three days In q darkenctl
room TO remove It's effects. This, he said, was
IN Illustration OF the persistence OF light. To
Indicate how waves OF light may be conducted
10y the sun 10 the earth, he produced q music.
box, and, after starting ~ be placed It In case
one end Of which he inserted iu hole in the
case, bringing II In contact with the music-bo
the tones were distinctly heard. The music
box, he said, represented the sun, the sound the
light, the rod the ether, and the guitar the
earths atmosphere, the whole beautifully Illus
trating the idea OF the transmission OF light
Ia further Illustration OF the persistence of
ducing an Intensely brilliant light, and called
upon tho audience TO observe how, after gazing
eye after they had disappeared. The same prop
erty OF dead substances was strikingly shown by
The subJection Of case Of phosphorescent tubes
10 strong light, and after 1t was withdrawn the
tubes were seen to he luminous.
A beautiful Illustration Of the fact that
COLOR DEPEN.s UPoN THE INTENSITY OF LIGHT
or the rapd,ty OF its undulationslwas shown by
the exhibition of q strip OF Magenta silk upon
which was how OF green ribbon. In yellow
IL ;ht they appeared Of duh brownish hue, wi lille
uuder strong Jet OF glare the true colors were
brought out with Intense hrilllance. The ladies
Were especially pleased with this experiment.
Wnile tho yellow light was turned on the Pro-
fessor and his attendants presented singular
saitensS iaugncd At Ills, but the Professor re-. u.
marked that Il was not all on one side-if he had
leisure he could laugh at the audience, for they
nppearedt to him jGst exactly as he appeared W
But the most interesting Illustration OF the
persistence OF hight, and the effect Of 4 swift
series OF Impressions on the retina, was shown
by the photo-drome. At the back was q large
spokcd wheel capable OF 80 revolutions a min
ute. It's shadow was thrown on q white screen
behind by d strong light from o lantern Ia front.
Turning the large wheel the spokes disappeared
and there was seen only black rim. But, al
iached 10 the lantern was black disc, capable
OF q very rapid revolution, and having sits In IL
for the passage OF the light. Turning this sec
ond wheel or disc, through which the light was
shining upon the INST wheel then In rapid rcvo-
luton, these spokes In shadow gradually be-
came distinct, until as the revolutions OF the
disc became more rapid, the nrst wheel ap-
peared actually to stand still, although turning
us fast rs ever.
The Professor said that II was hard TO convince
some persons that the 1rst wheel did not really
stand still, but he thought he could demonstrate
The truth by another experiment. lie then
fastened to the wheel circular plane OF paste
bosr,, on which was drawn series OF circles
lines were formed. Starting the disc on The
lantern, these lines were varied IN the most sur
prislnR way, corresponding to the velocity OF the
disc, until finally, with both wheels ut their
swifiesf, the original figure on ths first wheel
came gradually out into distlnctness. DimIn-
ishlng the velocity OF the disc, the series Of
effects were seen IN reversed order.
At this point the Professor said he would with
out further delay present the feature OF the en-
iertainment for which he knew all were impa.
ticnt, to wit
TIE GHOST,
and excusing hiMself for the purpose OF making
some inal adjnS ments behind the curtain, hc
disappeared, white his attendants removed the
tables OF apparatus from the front OF the stage.
The Professor soon reappeared, and the cur
tam berng raised, an Interior cuTtained with |
crimson was disclosed, In which was seated an |
artist, engaged IN skeIching au antique vase.
Tired with his labOTs and dlscouraged with the
results, the arts: lnOSel despondngty around, |
when at the rear Of the interior there
appeared ghOslly female figure, emerged |
IN his own pursuit, and having for q model |
similar vase. The artist, In astonishment, ap- |
preached the figure, when 1t slowly vanished !
Resumlng his seat the figure reappeared. I'm
patient at the Intrusion he attacked 1t with a |
sword, but the steel passed harmlessly through |
the ghOstly body. Then he discharged a pistol |
at II, when the spectre caugat the bullet and |
threw II at his feet. Then the artist seized |
heavy cloth aud attempted to smother the figure, |