IMPROVEMENTS IN THE MANUFACTURE OF GLASS, IN THE METHOD OF FORMING OR SHAPING AND ORNAMENT- ING VESSELS AND ARTICLES OF GLASS, AND IN THE CONSTRUCTION OF FURNACES AND ANNEALING KILNS
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWIN
PETTITT, of Birmingham, in the County of Warwick, Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twenty-fifth day of
May, One thousand eight hundred and fifty, in the thirteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Edwin Pettitt, my exors, adñiors, and assigns, Her especial licence, full
power, sole privilege and authority, that I, the said Edwin Pettitt, my exors,
admors, and assigns, or such others as I, the said Edwin Pettitt, my exors,
adiñiors, or assigns, should at any time agree with, and no others, from time
to time and at all times during the term of years therein expressed, should
and lawfully might make, use, exercise, and vend, with England, Wales, and
the Town of Berwick-upon-Tweed, my Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF GLASS, IN THE METHOD OF FORMING OR SHAPING AND ORNAMENT-
ING VESSELS AND ARTICLES OF GLASS, AND IN THE CONSTRUCTION OF FURNACES AND
ANNEALING KILNS;" in which said Letters Patent is contained a proviso, that
I, the said Edwin Pettitt, shall cause a particular description of the nature of
my said Invention, and in what manner the same is to be performed, by an
instrument in writing under my hand and seal, to be inrolled in Her Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said in part recited Letters. Patent, as in and by the
same, reference being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Edwin Pettitt, do hereby declare that the nature of my said Invention, and
in what manner the same is to be performed, are particularly described and
ascertained in and by the present Specification thereof, reference being had
to the Drawings hereunto annexed, that is to say:-
Firstly, my Invention.consists of a machine for mixing the crude materials
of which glass is composed previous to their being introduced into the melting
furnace. Figure 1 is an elevation, partly in section, and Figure 2 a plan of
this machine. A, A, is a circular case with a concave bottom B; C is an
upright shaft which carries a set of radial arms D, D, D, each of which is
furnished with a set of beaters E, E, E, projecting at right angles therefrom.
The case is stationery, while the vertical arms and beaters can be put in
motion at pleasure through the intervention of the wheel gearing F, F. The
materials are thrown into the top of the case by the doors G, G, and after
having been sufficiently mixed by the revolution of the beaters are removed
through the side doors H, H.
Secondly, my Invention consists of certain improved methods of forming.or
shaping and ornamenting vessels and articles composed in whole or in part of
glass. I employ for this purpose moulds composed of silica or silicious earth,
rendered plastic. by means of mucilage of gum tragacanth or any other
suitable mucilagenous matter. While in the plastic state the mixture. is
formed into moulds of the required shape by being pressed upon or into a
pattern of the vessel or article which is required to be reproduced in glass.
The moulds are then dried, and afterwards hardened by heat. These moulds
will of course be formed in one or more pieces, according as the general out-
line of the article formed may require for its delivery when formed, without
injury to itself or the pattern. The silica or silicious earth and mucilage form
a mixture which is a bad conductor of heat, and therefore does not deprive
the glass, when poured or pressed or blown into the moulds, too suddenly of
its caloric, by which means much better and sharper impressions of the
various parts of the vessels or articles are obtained than when brought imme-
diately into contact with metallic surfaces. Sometimes I coat the surfaces of
metallic moulds employed for shaping vessels or articles of glass with the non-
conducting mixture of silica or silicious earth and gum, for the same purpose
of obtaining sharper impressions of plain and ornamented vessels and articles
of glass; and in some cases it may be also necessary to coat the non-conduct
ing substance itself with plumbago or graphite, or other like suitable material
in order to prevent still more surely the adhesion of the glass to the mould
Moulds formed in any of the ways which have just been described, or moulds o

page_text: any other construction and composition, may be employed for the purpose of
ornamenting the vessels and other articles cast from them, that is to say, in
so far as respects the colours, devices, or designs imparted to them. This
part of my Invention is carried into effect in the following manner :-I take
any of the various metallic oxides, or pigments, or enamels, ground to an
impalpable powder, and mix them in a similar manner to that in which they
are now employed in the ornamenting of articles of glass, pottery, and porce-
lain, with more or less of the flux or fluxes adapted to each respectively, or
mixed with water or any of the hydrocarbons or mucilages, and then apply or
paint the oxides, or pigments, or enamels so formed into a paste upon the
various parts of the moulds or tables, where tables are used, according to the
colours or devices or designs to be produced upon the different parts of the
glass vessel, or other article. When the molten glass is poured, pressed,
rolled, or blown into the mould or upon the table, it will combine with the
different colouring matters, and assume the desired colours, devices, or designs.
Sometimes, instead of the preceding process, the vessels and other articles are
moulded, or blown, or rolled in the usual manner; and after being annealed
the devices are painted upon them, with the oxides, piginents, and enamels
prepared as aforesaid; the vessel or other article is then reheated to prevent
fracture, and dipped into the molten metal, which brings out the various
devices, and at the same time embeds or envelopes or encloses the same within
the body of the glass. In general, instead of employing the metallic oxides
or pigments alone for producing the colours, I prefer colored glasses or enamels
ground to a fine powder, as being more economical and capable of producing
more variegated effects with greater certainty. Sometimes I embed. pieces of
metal that have been previously cut, stamped, or cast into ornamental forms
or otherwise in combination with the painted designs or devices, and then
imbed or enclose them, as before described. Plates or sheets of glass may
be ornamented by forming designs or ornaments, either painted or stencilled,
with pigments, colours, coloured glasses, or enamels, in a state of fine powder
or paste, and applying the same to one side of the plate, which is then brought
to a heated state by being placed in a kiln or furnace; and while thus heated
another plate is cast upon or incorporated with the plate so ornamented, the
second plate being placed or rolled over the pigments or colours so as to
inclose or embed the design or ornament in or near the centre of the incor-
porated plates of glass; or the design or ornament may be depicted upon a
thin sheet of glass, and then embedded by casting and incorporating between
two other plates or sheets, being afterwards ground and polished in the usual
manner. Sometimes I enclose or imbed in or combine with plates or tables

page_text: of glass, pieces of solid glass, plain or colored, or of metal, which have been
previously stamped or cast or cut into ornamental forms, either by laying the
same on a table or flat surface, and then casting a plate or sheet of glass over
them, or by applying these pieces of glass or metal first to the surface of one
sheet of glass, and then casting, or rolling, or superimposing another sheet of
glass over and upon them. This method of imbedding or enclosing pieces
of solid glass, plain or colored, and of metal within glass, is particularly
applicable to, the making of pannels for walls, sign tablets, monumental slabs,
&c. One plate of glass may be opaque, and the other transparent, or of any
colour or tint to suit the character of the design. The ornamental pieces of
metal, instead of being stamped or cast or cut, as above described, may be
formed upon the surface of the first plate of glass by means of the electrotype
process. The design in this case is painted or drawn in upon the plate with
plumbago, and then connected with a galvanic battery, for the purpose of
depositing the metal by the same process as is now employed for precipitating
metals from solutions of metallic salts upon surfaces, and which process is well
understood.
Thirdly, my Invention consists of certain improvements in the method or
methods of casting plates or sheets of glass, and of rolling and casting pipes
or tubes of glass. Figure 3 is a longitudinal elevation of part of an apparatus
for rolling glass; Figure 4 is a cross section of the same. A, A, is a roller
which is mounted in bearings B, B, attached to the general framework C.
D is the casting table which is mounted upon a set of flanged wheels similar
to those employed on railway carriages, and by which the table can be drawn
forward and backward upon the rails E, E, underneath the roller A, A. The
glass to be rolled is poured in front of and close to the roller (as at the point
F) by means of a ladle or by a cistern, in the same manner as is now gene-
rally practised. The casting table is then, while the glass is in a plastic state,
drawn forward in the direction of the arrow by means of a windlass or other
suitable mechanical power. As the table advances it draws the glass under-
neath the roller A, which reduces it to one uniform thickness of plate. The
table, with the plate or sheet of glass thus formed upon it, is removed directly
into the annealing kiln without displacing or disturbing the plate of glass
itself. The thickness of the sheets or plate can be adjusted with great accu-
racy by the screws G, G, which act upon the bearings B, B, so as either to
raise the roller up from or bring it closer down to the upper surface of the
bed of the table. At the ends of the roller there are two flange-like discs H, H
separate from it, although mounted upon the same shaft; and while the rolle
revolves they remain stationary; being attached to the frame they serve to

page_text: prevent the glass from flowing over the edges of the table. The casting table
may be formed of metal, or of stone, or of slate, or of clay, or of a vitreous
substance, or of metal, or stone, or slate, or a vitreous substance covered with
clay or with cement, or with clay mixed with silicious substances, or plumbago,
or any other substance which is a bad conductor of heat, or any other suitable
combination of bad conducting substances; or the casting table may be formed
wholly of any one of the said bad conducting substances themselves, or of a
combination of two or more such substances. In some cases I coat the tables
with plumbago or other anti-adhesive substances.
Figure 5 is a part plan, and Figure 6 a part longitudinal section, of another
arrangement of machinery for casting glass. A, A, is supposed to be the
bottom or sole of a casting and annealing kiln, and is composed of or covered
or coated with some one or more of the substances or combination of two or
more of the substances above enumerated as employed for forming the casting
table; B, B, are two rails; C is a roller for spreading out the glass into a
plate or sheet; D, D, is a receiver made of metal lined with fire clay, or com-
posed entirely of fire clay (in which last case the vessel must be supported in
a metal frame), into which the molten glass is ladled from the melting furnace.
Both roller and receiver are connected together and are drawn forward upon
the rails B, B, by means of the chains E, E; F is an opening through which
the glass flows from the receiver on to the surface of the table or sole of the
kiln; it is closed during the operation of filling, but when opened for the glass
to issue out, then the receiver and roller are made to advance and spread the
metal into a continuous plate or sheet upon the table or sole of the kiln,
which is afterwards annealed by slowly cooling the kiln.
Figure 7 is a side elevation of part of a casting table, shewing a method of
employing guides for giving steadiness to the roller in place of the racks and
pinions now usually employed. A, A, is part of the framework of the casting
table; B, one of the guides, which are attached to the frame of the table,
by means of regulating screws; C, the roller for spreading out the glass into a
plate or sheet; and D, the chain by which the roller is drawn over the table.
Figure 8 is a side elevation, and Figure 9 a front elevation, of a pair of
rollers which are employed for the purpose of forming glass pipes or tubes.
A, A, are rollers which are grooved upon their surfaces, so that when any two
opposite grooves are brought together they may form circles; B is a metal
mandril or core, which is coated upon its surface with clay, or any of the bad
conducting substances before mentioned. This mandril being dried, one end of
it is dipped into melted glass, and a sufficient, quantity of the metal is raised
up or gathered upon it to make the intended pipe; the mandril or core, with

page_text: the glass adhering to it, is passed through the rollers, which draws the glass
into a pipe or tube, after which it is annealed with the mandril or core
still remaining inside. When so annealed the mandril or core is withdrawn
to be again used for the same purpose. Sometimes a thin ribband of glass
is wound spirally over the mandril, as exemplified in Figure 10, and while
the ribband of glass is in a heated state it is passed between the rollers, so
as to unite the edges and bring the pipe or tube to a proper form. The
pipes or tubes are supposed, in the preceding description, as being of a circular
form, but they may obviously be made of any required form or figure by
making the mandril or core and the grooves in the rollers of the particular
form or figure required.
Figure 11 is an elevation, and Figure 12 a cross section, of a machine for
forming glass pipes or cylinders by means of centrifugal action. A, A, is a
cylinder which is mounted upon the axes B, B, by means of the end discs
C, C. The molten glass is poured into the cylinder A, A, by removing one of
the end discs, which is again replaced, and the cylinder caused to revolve with
considerable velocity by a band carried over the pulley D. The centrifugal
action causes the glass to arrange itself all round the inside surface of the
cylinder, and the rotative action is continued until the glass sets, when the
cylinder, with the pipe thus formed in it, is removed to the annealing kiln by
means of the crutch, shewn separately in Figure 13.
Fourthly, my Invention consists of certain arrangements in the construction
of glass furnaces, by which the production of "tears" or drops is in all cases
prevented; the expensive pots and cisterns now used for holding and fusing the
metal, as also the sieges are entirely dispensed with, and a great saving of the
fuel required for fusing the metal is effected.
Figure 14 is an end elevation, Figure 15 a vertical cross section, and
Figure 16 a plan, of a furnace constructed according to my said improvements.
A, A, are fire rooms; A³, A2, the fire doors; B, B, the furnace bars; C, C,
the ashpit; D, D, inclined walls which form the roof of the fire rooms, and
cause flame and heat to be deflected through the openings E, E, over the
surface of the metal or "glass mixture" contained in the cells F, F, from
which they are conducted by the openings G, G, into the cone or chimney,
which, being of the usual construction, is not represented in the Drawings.
The cells F, F, serve all the purposes of the pots now in use for fusing glass.
The walls of the cells are in the first instance formed of fire brick or fire stone,
lined internally with clay (by preference Stourbridge clay); H, H, are move-
able stoppers or covers of fire clay or fire stone, or other suitable materials,
which form the entire roof of the cells F, F, and are the only parts which

page_text: In a short
overhang the surface of the metal when the furnace is in use.
time the combined action of the heat and alkaline vapours from the glass
mixture would, if not counteracted, naturally cause a dropping or falling of
"tears" to take place from the lower surface of these stoppers; but as soon
as there is any danger of this taking place they are either removed or simply
turned over, that is, upside down. The attendant upon the furnace must take
care that the lifting off or turning over of the stoppers is performed some time
previous to the generation of the tears upon their under surface, which is
easily ascertained on inspection. Hitherto the pots have been placed on
sieges in the body of the furnace, which has made it generally necessary, when
tears or drops are produced, to pull the whole structure down, with the exception
of the cone; but in my improved furnaces the moveable stopper being
removed and replaced by a fresh one when there is any tendency to fusion or
dropping, the furnace may be continued to be used until the whole of it is
worn out. It will be observed, on reference to the Drawings, that the fire
chambers run parallel with each other, and leave an angular space I, I, between
the inclined walls D, D; this space is filled in with sand, or may be employed
for drying the sand for the glass mixture. The molten glass or metal is
removed from the cells F, F, by means of ladles in the usual manner in
The
which glass is now lifted out of the pots into the cisterns or curvettes.
removal may be effected either through the working holes G, G, or by lifting
the moveable stoppers and taking it out at the top of the cell.
Figure 17 is a vertical cross section of a modification of the furnace just
described, differing from it only in having a single fire chamber A with an
arched roof B, instead of the deflecting walls. C, C, are the fire bars, which,
like those in the preceding case, form inclined surfaces upon which the fire
rests; they may be also laid in a horizontal position, but I prefer the inclined.
Figure 18 is a side elevation of one of these improved furnaces, shewing
how melting pots or cisterns may be used in connection therewith. The
outside walls of the cells F, F, have openings F, F, in them, through which
the pots or cisterns are put in and taken out when necessary. These openings
are closed either with brickwork or by moveable stoppers or slabs; L, L,
are the working holes, and H, H, the stoppers which form the moveable roof
of the cells.
Figure 19 is a vertical cross section taken on the line a, b, of Figure 20,
which is a plan of one of my improved glass furnaces, where the cells or
the pots are arranged in a circle around the fire room. A is the fire room;
B, B, the furnace bars; C, a pipe or aperture by which air, either in a heated
or cold state, is supplied to the interior of the fire room; D, D, are the

page_text: openings from the fire room into the cells F, F, which cells may be of the kind
first herein-before described or supplied with pots, as represented in the Draw-
ings; G, G, are the working holes, and I, I, passages for firing the furnace.
Figure 21 is an elevation of a furnace similar to that shewn in Figures 19
and 20, differing from it only in having two tiers of cells or pot chambers.
G, G, are the working holes, the lower set of which are situate just above the
ground line, and H, H, are the moveable stoppers or roofs.
Figure 22 is a vertical cross section of a glass-melting furnace, and Figure
23 a plan, one half of which is in section, taken on the line a, b, of Figure 22.
A is the fire room; B, a boiler for generating steam to be employed in com-
municating motion to the machinery employed for grinding and polishing glass,
or for supplying a jet of steam in the chimney to produce a draft of air through
the furnace; this boiler is placed longitudinally over the fire room, to which it
serves as a roof. F, F, are the cells or pot chambers; H, H, the moveable
stoppers, and K, K, descending flues, by which the products of combustion
are conveyed to the chimney L. This arrangement of furnace with a chimney
admits of the cone being dispensed with, the jet of steam creating the draft
requisite to produce the necessary heat for the fusion of glass. The working
holes may be either formed in the moveable stoppers II, II, or in the tops of
the descending flues K, K. In all cases where pots are used in the cells I
prefer to embed them in sand, excepting in cases where the pots are to be
taken out at every casting.
Figure 24 is a vertical section taken longitudinally upon the line a, b, of
Figure 25, which is a plan partly in section, shewing the manner of combining
and working together a set or series of furnaces for the purpose of economis-
ing fuel. A, A, are the fireplaces; B, B, the fire bars; C, C, C¹, C¹, the
melting cells or pot chambers in which the glass is fused; D, D, are openings
by which the whole set or series of fireplaces and melting cells are connected
together, so that the flame and heated products of combustion arising from
the fireplaces furthest from the chimney E must pass through the whole of
the fireplaces and melting chambers nearer to the chimney. The set of melt-
ing cells C, C, which are represented as occupying the position to the left of
the chimney, are intended for melting such glass as it is not necessary to
protect from contact with the flame of the furnace, while the other set C', C',
shew the same principle of applying the heat to the melting of glass (flint
glass for instance), upon which the flame and products of combustion would
produce injurious effects if allowed to play over the surface or come in contact
with the molten mass.
Figure 26 is a part front elevation, and Figure 27 a cross section of the

page_text: melting cells C, C. Figure 28 is a part front elevation, and Figure 29 a cross
section of those marked C¹, C. The cells C, C, are covered with moveable
stoppers or covers II*, H, similar to those employed in the melting furnaces
before described. The other cells C', C¹, contain melting pots, which are
covered with moveable hoods or stoppers F', F', of fire clay, having openings
in them F, F, through which the metal is taken out or worked. F, F, are
flues for carrying off the alkaline vapours disengaged during the fusion of the
glass. The number of melting cells arranged in one continuous line may
vary according to circumstances, but it is necessary that they be provided
with auxiliary flues, by the use of which any one or more of the set of melting
cells and fireplaces may be stopped out, while the others continue in work.
G, G, are the auxilliary flues communicating with the fireplaces by the pas-
sages H, II, which are provided with stoppers or dampers capable of closing
these passages when required. Suppose, for instance, it is found necessary to
shut off the intermediate melting cell I, then the passage De leading from the
fireplace through that cell is closed by a damper or stopper, and the passage
His opened, as also the next passage H³, whereupon the flame will follow
the course indicated by the arrows, and leave the melting cell I free from the
action of the fire.
In the Drawings of the furnaces represented in Figures 24, 25, 26, 27, 28,
and 29, there is only one single cell or melting pot to each fireplace, but
two, three, or more may be employed, as, for instance, when the pots or cells
are very shallow.
Figure 30 is a longitudinal section, and Figure 31 a cross section, of a
combined arrangement of reverboratory furnaces, in which the principle of
action, in so far as regards the application of the heat successively to the
whole of the melting cells in the series, is carried out. This furnace may be
employed for the melting of glass, the smelting, puddling, or working of
metals, or for roasting of ores, and other purposes to which reverberatory
furnaces are applied. A, A, are the fireplaces; B, B, the melting cells or
chambers; D, D, the flues connecting them; and E, an auxiliary flue, all
as before.
Figure 32 is an elevation, Figure 33 a longitudinal section, and Figure 84
a cross section, of an earthenware or fire-clay apparatus, which I employ for
supplying air or steam to the interior of a furnace, when a supply of either
of them is of advantage. A, A, is an interior chanıber; B, B, a set of
pipes opening into the furnace; and C, C, are ledges upon which the fire
bars rest.
Fifthly, my Invention consists of an improvement in the construction of

page_text: the kilns for annealing the glass. Figure 35 is a longitudinal section and
Figure 36 a cross section of an improved annealing kiln; the body or chamber
is composed chiefly by or entirely of iron plates resting upon masonry.
A, A, A¹, A¹, are the plates which form the walls or boundaries of the kiln.
Between the plates A, A, and A', A', there is an intervening space A, which
is filled with air, or with some material which is a bad conductor of heat,
such as sand or clay. B, B, are fireplaces; C, the flues; D, D, rails upon
which the casting tables are conveyed into the kiln. When air is employed
for filling the space A2, A3, the plates covering the 'flues are perforated to
allow of a free circulation of heated air throughout that space.
Sixthly, my Invention consists of certain improvements in machinery for
grinding and polishing plates or sheets of glass. Figure 37 is a vertical
section of a grinding and polishing machine. Figure 38 is a plan of the same.
A, A, is an upright shaft which has its bearings in the framework B, B, and
has firmly keyed upon it the horizontal grinding table C, upon the upper
surface of which the glass to be ground or polished is affixed in the usual
manner. D, D, are four other spindles or shafts, which also have their
bearings in the framework B, B, and give motion through the medium of the
cranks E to the upper tables or runners F, F. Motion is communicated to
the upright shaft A from some prime mover by the horizontal shaft G and
the wheel gearing H; H, whereby the table C and the glass affixed upon it
are made to revolve. The spindles D, D, have at the same time motion com-
municated to them through the bands I, I, and pullies K, K, K, which cause
the upper tables or runners either to revolve in a circle around the centre of
their spindles, or by means of the radius bars L, L, to describe partly a
circular and partly a to-and-fro motion, by which means a constant change
of the positions of the rubbing surfaces is effected, and the grinding process is
consequently greatly facilitated. On the horizontal shaft G is a clutch box, for
the purpose of throwing the tables in and out of gear. When the machine is
used for grinding the lower surface of the upper tables or runners may either be
of metal or covered with plates or sheets of glass. When the sheets or plates
have been reduced by the grinding to a proper surface, there are substituted
for these tables or runners polishing tables of the construction represented in
Figure 39, each of which consists of an upper framework a, a, having affixed on
the lower side bars of metal b, b; bars of wood covered with felt may be sub-
stituted for these metal bars, or the table may be composed of a single plate
of metal, or of a table of wood covered with felt.
Figure 40 is a vertical section, and Figure 41 a plan, of a grinding and
polishing machine, which is a modification of that last described, differing only

page_text: in the variable motion given to the upper tables or runners, which is produced
by means of sliding pins c, c, in the cranks E, E, these pins moving freely in
slots formed in the arms of the cranks. The lower ends of these pins are
attached to the tables, and their upper ends project beyond the surface of the
crank arms, and take into elliptical grooves d, d, formed in the plates M, M,
which are affixed to the general framework. By this arrangement the upper
tables or runners or polishing tables are made to travel in an elliptical course,
which causes a constant change of the parts of the rubbing surfaces to take
place.
Figure 42 is longitudinal section of one of these upper
tables or runners,
showing how a circular motion may be easily given to the tables by means of
the machine last described. For this purpose the upper end of the crank pin c
taking into the elliptical groove d, d, is removed, and the pin secured to the
arm of the crank E by means of a nut c.
During this part of the
Figure 43 is a longitudinal section, and Figure 44 is a plan, of another
grinding and polishing machine. A, A, is the table upon which the glass plate
or sheet to be ground and polished is laid; B, B, are a set of rollers by which
the table is carried; C, a rod which connects the table with a crank D,
which is driven by some prime moving power, and causes the table to par-
take of a to-and-fro motion upon the rollers B, B; E, E, are a set of
grinding and polishing rollers, which may be made of metal or stone, and
are mounted upon a framework F. The entire set of rollers is put in motion
through the intervention of the wheel gearing G, G, G. The power for giving
motion to these wheels is applied to the wheel II, which has its bearing upon
the spindle I, upon which the frame F is hinged. The plate or sheet of glass
is bedded upon the upper surface of the table.
operation the frame F and the rollers are raised up from the surface of the
table by means of the chain K, the table moving upon its axis I.
the glass is fixed the frame F is lowered down into its place; a slow motion
is then given to the table by the crank and connecting rod, and at the same
time the rollers E, E, are made to revolve at a greater rate of speed. The
grinding or polishing material, such as emery, sand, crocus, &c., is supplied
between the rollers, and speedily reduces the glass to the required thickness
and surface. The frame F, as well as the bearings of the rollers, have
stops, by which the extent to which the grinding is carried may be regulated.
Figure 45 is an elevation on an enlarged scale of two of the end bearings
of the rollers, showing the arrangements necessary to be made to enable those
rollers to yield to any considerable unevenness which may be upon the surface
of the glass in the first instance when put into the machine. a, a, are springs
When

page_text: inserted into the upper side of the brasses forming the bearings, which are
free to slide up and down in slots formed in the sides of the frame F. The
springs a, a, together with the weight of the roller, always ensure the rollers
grinding the surface of the glass, until the bearings come down to their
proper level.
Figures 46 and 47 are separate views of single rollers, shewing different
kinds of surfaces which may be given to the grinding or polishing rollers.
The machine represented in Figures 43 and 44 is applicable for polishing
as well as grinding, and, when used for polishing, the rollers may be made
of metal alone or of wood alone, or of wood covered with felt or leather, or
other suitable material. The metals most suitable for this purpose are lead,
tin, zinc, copper, iron, and steel; compound metals may be also employed. In
every case the nature of the glass and the material used for polishing, together
with the speed of the rollers, will determine the metal most proper to be used
for this purpose.
Figure 48 is a cross section of a grinding or cutting machine similar to
that last described, but differing from it in the following particulars:-The
bottom table A is a fixture, and the rollers B, B, are each composed of a
number of discs fitted upon an axle, or of solid metal rollers turned out to
any of the different forms of beads or collars shewn at B1, B2, B³. This
machine will be found especially applicable to the formation of slots or
openings in sheets or plates of glass. The glass to be perforated is laid upon
the table; motion is then given to the discs or rollers, and a grinding material
supplied at the same time. The weight of the rollers or other pressure applied
to the framework in which they are mounted, together with the speed at
which they revolve, cause them speedily to grind or cut through the sheet or
plate of glass. The upper surface of the table upon which the glass is fixed
is grooved out for the purpose of receiving the discs after passing through the
glass.
Figure 49 is a longitudinal section of a machine for perforating simul-
taneously a series of round holes in a plate or sheet of glass. A, A, is the
table upon which the glass is fixed; B, B, a frame carrying a set of spindles
C, C, each of which has a small toothed wheel upon it; the whole set of
wheels gear into each other and revolve together in one system; each spindle
bas at its lower end a metallic drill or perforator. When the drills are put
in motion and supplied with grinding material, such as oil or turpentine alone,
or emery or sand mixed with oil or water, the frame is allowed gradually to
descend until the drills have perforated the plate or sheet of glass.
And having now described the nature of my said Invention in the several

page_text: parts thereof, and in what manner the same respectively are to be performed,
I declare that I claim as follows:-
First, I claim the mixing machine represented in Figures 1 and 2, and
before described, in the general arrangement and combination of parts of which
the same consists.
Second, I claim the employment in the forming or shaping of vessels and
other articles of glass, of moulds composed in whole or in part of a mixture
of silica or silicious earth and mucilage, as before described.
Third, I claim the ornamenting of vessels and other articles of glass by
laying coloring matters in a powdery or pasty state upon the moulds from
which the same are cast, or by incorporating of such powdery or pasty coloring
matters into the body of the glass, both processes as before described.
Fourth, I claim the ornamenting of vessels and other articles by imbedding,.
enveloping, or enclosing therein, or combining therewith, pieces of glass, plain
or colored, or of metal, previously stamped, cast, or cut into ornamental forms,
or films of metal precipitated by electricity, of certain previously determined
forms, both processes as before described.
Fifth, I claim the ornamenting of plates and sheets, and of vessels and
other articles of glass, by a combination of any two or more of the aforesaid
processes, or of any one or two or more thereof in combination with any known
process or processes.
Sixth, I claim the apparatus for casting plates of glass, represented in
Figures 3 and 4, and mode of using the same before described; that is to say,
in so far as regards: the materials of which the casting table is composed, the
causing of the table to move under a stationary roller, which is made to rotate
by the motion of the table, and the annealing of the glass before removing it
from the casting table.
Seventh, I claim generally the constructing of tables or surfaces of tables
for casting glass of materials and compounds of materials being bad conductors
of heat, as before exemplified and described.
Eighth, I claim the apparatus for casting, represented in Figures 5 and 6,
and before described, in so far as regards the combination of the roller with
a receiver, and the mode in which these two parts of the apparatus are worked
in unison, and in so far also as regards the casting of the plates or sheets of
glass on the sole of the annealing kiln, and the construction of the sole
of the aunealing kiln so to be used wholly or in part of bad conducting
substances.
Ninth, I claim the casting table, represented in Figure 7, and before

page_text: described, in so far as regards the employment of guides for steadying the
roller and regulating the thickness of the plates.
Tenth, I claim the method of forming tubes or pipes of glass by means of
grooved rollers and mandrils or cores, as before described.
Eleventh, I claim the method of forming cylinders of glass by centrifugal
action, as before described.
Twelfth, I claim the different constructions of glass furnaces, represented in
Figures 14, 15, 16, 17, 18, 19, 20, and 21, in so far as regards the substitu-
tion of cells for pots (either wholly or in part), and the angular inclination
given to the side walls, the employment of moveable covers or stoppers, and
the mode in which (in certain cases) air is introduced.
Thirteenth, I claim the forming of the roofs of furnaces employed for the
manufacture of glass of boilers laid longitudinally (or otherwise) over the same,
as exemplified in Figures 22 and 23, and before described.
Fourteenth, I claim the method of arranging and working a series of
furnaces, represented in Figures 24, 25, 26, 27, 28, and before described,
as also the modification of the same, represented in Figures 30 and 31, and
before described.
Fifteenth, I claim the apparatus for applying air or steam to furnaces,
represented in Figure 32, and before described.
Sixteenth, I claim the mode of constructing annealing kilns, shewn in
Figures 35 and 36, and before described.
Seventeenth, I claim the improved machines for grinding and polishing
glass, represented in Figures 37, 38, 39, 40, 41, and 42, in so far as regards
the arrangements by which the bottom tables are made to revolve simulta-
neously with the upper tables, the combination thereby effected of the grinding
and polishing machinery, and the arrangement by which an elliptical motion is
given to the upper tables or runners.
Eighteenth, I claim the improved grinding and polishing machine, repre-
sented in Figures 43, 44, and 45, and before described, in so far as regards
the combination of a reciprocating table with a series of revolving rollers, in
manner there represented.
Nineteenth, I claim the grinding and cutting machine, represented in
Figure 48, and its application to the production of slots or openings in plates
or sheets of glass, as before described.
.
Twentiethly, I claim generally the application of metallic surfaces to the
grinding and polishing of plates and sheets of glass, in manner before exempli-
fied and described. And,

page_text: Twenty-firstly, I claim the machine for perforating or drilling holes in
plates or sheets of glass, as represented in Figure 49, and before described.
In witness whereof, I, the said Edwin Pettitt, have hereunto set my
hand and seal, this Twenty-fifth day of November, in the year of our
Lord One thousand eight hundred and fifty.