New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1857-08-27
IMPROVEMENT IN THE MANJFAC TURE
or PLATE GLASS.

plLy asciibe5 the discovery OF glass 10 accldenl.
laden with naron was stranded at the
entrance Of the river Bes in the morning the sailors
lighted fire shore to prepare Breakfast and placed
around it few pieces Of naron to sustain the kettle,
the na.ron combining with sand produced transpa'
rent body to the great wonder of the sailors VINO as
crbed to the sand Of the place peculiar virtue This
prejudice left to the Phpnicans the exclusive prOduc
ton of glass for centures it was an admitted fact
that only the sand found in the vicinity Of Mount
Carmel was capable Of producing glass ami when in
course of time this manufacture extended to other
countries, the sand was imported from Phenica. The
researches Of Berzeius have shown that glass is a
siicate either of potash Of soda OF lime OF alumna
of oxyde of iron or of lead. The glass is paued ac-
cording to the nature OF the slkal
The elements Of Plate glass are Sand and coda 10 Tie
proportion Of three parts of sand TO Of the carbon
ate of soda. The manufacture of window glass began
in England in 1851 that OF Mirror plates began in
France in 1888. The celebrated establishment ot ST.
Gobain, France founded shortly after this date re
manned for accntury in the exclusive pos'easion
Of this manufacture and la, never bee
rivalled except by the Engl:h. TIE company
that owns it has been made rich By enormous
profits. and they either buy off those woo attempt
competition or ruin them by uRderselirg. Tae raj
of St. Gobain is Ia by l2O feet that Of Raverhed
the largest glass factory in England is S59 W LOO
In 1862 England exported 100000 worth OF plate
glass. TIE importation into the United States is about
IS, COO 900 year.
The process of making plate glass aaer the glass |,
melted consiNs: |. In pouring 1t upon cast iron
table with turned up edges, ard Immediately passing
heavy metal cylinder over ii in order to give tue
glass an eqls, thickness. =. In anneaLng u ID
ovens. g. In grinding ard polishing. To perform this
last operation the glass is placed on table imbedoed
in plaster Of Paris coored red to show any ceiec 10
the glass. Another plate about quarter OF the SIZE
of the first is placed over it. aud upon THE pvamdal
stone is cemented with plaster the weight OF the stone
beirg calculated at one pound TO the square INCH
Emery is poured on the glass, aud the snail one ~
rubbed over the other by hand. The polishing Is
done in a similar manner by using red oxyde OF iron'
and the finishing is done by friction with felt.
The machine we saw Yesterday. a. the invitation ~
the United States Manufacturing and Poishn g Plate
Glass Company, is intended to perform the grading
and polishing by power. Ii Is the Invention oi a'
Brougton, improved by Mr.. p. Burgess TIE grncer
is a horizontal circular plate OF cast-iIon, ~ feet IN
diameter ard inches thick. The upper surface 10
blamed and has ribs beneath to give it strength Thi'
large plate is keyed on the end of vertical shaft,
which Is made 70 reyolye at velocity OF forty .hge
revolutions minute. Two ho.se-pows. il al that "a
required The plate OF glass to be ground Is placed
upon the circular table just described; usif-say be-
tween the center and tie circumference adjustable
frame of the proper weight is placed upon il 50 az %
confne the edges and prevett the plate from slipping
away This frame carries in its center a round rod.
STANDING vertically. which i. kept in ts place by two
bars fastened to the frame OF the maesne.
This arrangement prevents the hame from moving
away, but does Lot prevent 1t rom rcVoI'-nS'
There is room On the circular table for four gas
plates disposed in similar manner ~ cistanae tfcL
the center trough full Of sand with az aperture
in tie bottom proportional to tie quantity OF sac fe
qured, is suspended above. The machine q put
in operation by making The ten feet table re-
vove. The frames above being held IN theI
place the glass they cary Is rutbed o.
the table, and the velocity being greater at
the circumference OF the table than near the oetst
these fames themselves be gin to revolys in Contrary
direction This motion which is result " tie ,irsI
has the advantage IF regulating the friction by sue
cessively bringing every point of the glass; rear tos
center where the friction is Least, aud near The cls
cumfererce where i, is greatest.
The polishing machine IS nearly snils- 70 the g-inc'
ing machine. TIE only difference l. that ts upper
surface Is formed Of wooden rings covered With .st
which screwed uron the oas;.:-cc abis and that
these c;rcusr ring eccentric tctte table .nl.eays
between them parallel circua- ridges - nearly the
same breadth tire wooden rings. TIE glass plates
are placed upon this machine upor tie other 10
exactly the same br. instead CT as-3 falling
on it from box oxide OF uon or rouge thoroughly
mixed with 1a,s-, i used AID Il So pied .hs fe
with brush.
We saw YESTERDAY, pate OF glass taken from tie
grndirg m.chine aad placed the polishing tstle,
which came out OF the machine perfectly smooth -
On. side after ore teur tsk,s ten hours 20 Obtain
su:ls. resu.. By ha,i Iab9r TIL, grinding oachn 10