New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1871-02-06

broken
pens when an Opaque object . thrown on tnG sGr nep
nose tbe bar ~ glass Won see appears broken anu h
move Il the fracture appears on 30 In " sod
t raadnceS nv the action OF this piece OF glass
Now ia hold it so that the rays pass % ect az Eli
angles you see en Ia ~ ns large tank With water As
the lecturer pours, the tank appears a. bein1
have here n LIQUID ~ very high refractlng PDMfi ~ y
m TACT very dense will pour 1t IN irregu s anu me
will assume very complex and fantastic i9rns Inc me
s,oLe fT,m n crater rising in thin, black column,
errradng out with beautiful shinmerlng nv
Vet NV duid il Just clear water IL Is llrou ~
iremeiy pid Many OF you will have Just observer lne
effect that you have noticed over stove % bt ~ 10
rd the density is diminished and the reiracting
power is changed. Now In the next Plac a. caiifv ~
plain to you OF the Important results Vi 'i ' "
By means Of another large diagram the action OF ens
9lrn,oon ai nm Image was ucidy described diagram
rpreseniing an eye then appeared and tho lecturer ex
planned construction and the once 0l eaon I "a i,
ben alluded 10 the means afforded by tho eyes OF Judging
as To the distance Of objects and pointed V NV i ~
these are aud in illustration OF TINS eAnl'itou ''' "
First view Of the interior OF tunnel appeared upon
w. tb mont oconOtive which at the instant when It
eecd about 10 plunge into the orchestra. vanished
IN lie manner advanced beautiful statue hdeous
skull and rolling ball, all with the most perfect re-
sembance OF actual approach, and yet al 1, pGtuIes
ON the unchapgng surface OF tine screen Ihen iVlnS
figures seemed to advance from n bright DachErOuh1
nanc into Tie roof OF the house and DISAPPEARED only
10 lead down again and of into the distance once
We're developed the lecturer proceeded as follows: -
eye has additional properties nor ne 'ose 81 my
Ions When the light strikes upon the retlna produces
vbratory motion, and that yiDratory motion eoe5 1V
immediately cease IN any Gnoe a teb d" Of second
ii ray were exnguished and lighted 90 tlncS secohn
you would not perceive that 1t was eNtn6oheu ~ az
shall show YOU q great number Of Illustrations OF TINS
persistent vision. Ion are familiar with the Gaze 81
lighting tbe end Of a stick and whrling 1t round l IL
.lra on tII
made on the eye when the stick Is In one position ana
lasts tin it comes back again to the same positl0n anu III
the same way each position throughout the circle
Here again have an Illustration OF tne same S oy
what might call the developed chameleon Top. 10y an
apparatus which now place in the lantern throw on
the circle composed OF three Coors II that Is
rolled around one color that one Is pcrsisent-the 0ers
blend III we change the center OF rotation We change
the constant color Now change it, This contriVaco
enables to do thi, while the thing Is spinning as you
will see Floods OF red blue, purple PINK ana Whte,
poured ont from the center and flowed outward In sue
cessiyc rings with beautiful eject ELECTS piecSey Sil
tbs Which can he Illuminated with tho electric light
developed by this coil which Is tine most powerful OF us
kind now in the world If number OF these he
mounted on cara we gee Fno sras,tios civ
ing Kaleidoscope effect, which Is very beautiful;
when the gas was turned down and the electric 1uid
turned On the coOrs Of the Gesscr tubes, forming the
shapes Of snow crystals streamed through the hal'
green, purple, and yellow flashes appeared. new ap,
paratus being attached, burning sapphire, emerald ana
amethyst appeared. An arrow-headed card was next
orange imperial purple and pale green played over the
face OF the apparatur - You have here an apparent
star though the Instrument has but single point. There
are but three tubes you saw but by persistence OF
vision there appear Ia be great many more-six at
least" The beautiful green light which you see Is gwen
bv carbOnic acid which WAS observed in the comet No.
Of lsG3 You will also certain amount OF Dlurring
that is owing To the heavy discharges from this coil
curing a definite time Prof. Rood has succeeded in
measuring the duration of flashes Df lightning, and found
in opposition the general opinion, that they require
definite period 10 complete their discharge occupying
the five-hundredh one sx-hundredth part OF "A
second further illustration OF persistence or vision i
furnished by the lightning fash, which Is only point
though by this action il seems extended INTO "a long
Jagged line. This initiate with this coil and TINS
plate OF glass covered with brass filings.
"A great plate OF glass six feet high ana mounted
i'm a stand was then arranged and sparks OF dazzling
brightness accompanied by rlttng reports were caused
to spring over H. .
General applause testified to the approval Of tho audi
enco and their interest ia the lecture.