IMPROVEMENTS IN THE MANUFACTURE OF GLASS
Year: 1843

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
IIARTLEY, of Wear Glass Works, Sunderland, Glass Manufacturer, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Sixth day of July, in the seventh year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said James
Hartley, Her especial licence, full power, sole privilege and authority, that I,
the said James Hartley, my exors, adñiors, and assigns, or such others as I,
the said James Hartley, my exors, adññiors, 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, within England, Wales, and the Town of Berwick-upon-Tweed, my
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF GLASS;" in which said
Letters Patent is contained a proviso, that I, the said James Hartley, shall
cause a particular description of the nature of my said Invention, and in what
manner the same is to be performed, to be inrolled in Her said 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.
NOW KNOW YE, that in compliance with the said proviso, I, the said
James Hartley, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof, that is to say -

page_text: My Invention relates, first, to an improvement of the furnace used for
flattening sheet glass.
Secondly, my Invention relates to improvements in the flattening stone used
in flattening furnaces.
Thirdly, my Invention relates to the application of an improved bed or
surface for glass when the same is being ground or polished.
And, fourthly, my Invention relates to an improvement in the furnace used
for heating the "nose" of crown glass before "flashing."
And in order that the Invention may be most fully understood and readily
carried into effect, I will proceed to explain the means pursued by me.
And, first, in respect to the flattening furnace used for flattening sheet glass,
which, being made into cylinders, such cylinders are split and then flattened,
as is well understood. According to the present construction of a flattening
furnace, the workman, in flattening successive cylinders of glass in a furnace,
as fast as one cylinder is placed on the flattening stone to be flattened, another
is placed in the furnace to the right hand of the flattening stone, and as the
fire is on the left hand of the flattening stone, as the cylinder on the flattening
stone is being flattened, the cylinder of glass next to be operated on is becom-
ing heated, but such heat is chiefly on that side next the flattening stone, that
is, the side of the cylinder towards the fire, which becoming highly heated
will on that side begin to drop or flatten, whilst the other side of the cylinder,
that is, the part of the cylinder most distant from the flattening stone, being
comparatively little heated, will rotain much of its stiffness, and as the cylinder
on being moved on to the flattening stone is necessarily moved with its hotter
surface towards the fire, that surface will be liable to become burned, whilst
sufficient heat is being obtained to the other side of the cylinder in order to
allow of that part being also flattened.
Now the object of the first part of my Invention is to apply a rotatory stone,
on which the cylinders of glass to be flattened are successively put before going
on to the flattening stone, by which the workman, before removing a cylinder
on to the flattening stone, may turn it so as to bring the least heated surface
towards the fire, so that when on the flattening stone the least heated side may
be brought nearest the fire, by which means the side of a glass cylinder
which has become beated during the time that a previous cylinder has been
undergoing the flattening process, and which is ready to be flattened, will be
turned furthest from the fire, and thus will both parts or sides of the cylinder
be more conveniently flattened without one side being liable to become too
much heated.
In carrying out this part of the Invention at the right of the flattening stone

page_text: in the position where the cylinders are usually put preparatorily to their being
moved on to the flattening stone, I apply a flat circular stone of about ten
inches diameter, on the under surface of which I aflix an axis, and cause that
axis to turn in suitable bearings, so that the workman may readily push the
stone round with a cylinder of glass upon it. It is well known that there is
much difficulty in getting sheet glass
truly level on the flattening stone, and
one of the obstacles is the air which is under the glass.
Now the second part of my Invention consists in forming numerous small
holes through the flattening stone or bed, so that the air may readily get away
from under the glass as the glass becomes more and more flat. In carrying
out this part of my Invention, I form holes about an inch apart, each hole
being an eighth of an inch or less in diameter, which I have found sufficient,
but I do not confine myself thereto. By this means I am enabled to perform
the process more advantageously, and although sheet glass so flattened is liable
to be marked, this is not material when the glass is to be afterwards ground
and polished; and it is of great importance to obtain such thin glass, when to
be ground and polished, as flat as may be.
Invention, which relates to the
holding glass when the same is
other sheets of glass, in order
I will now describe the third part of my
application of an improved bed or surface for
being ground or polished. In fixing plate and
that the same may be ground and polished, it has been usual to employ plaster
of Paris, and in some cases, when grinding and polishing thin sheets of glass
capable of bending, other means of holding the same on smooth and unyielding
surfaces have been resorted to. Now this third part of my Invention consists
in applying surfaces of india-rubber on which the plates or sheets of glass to
be ground or polished are to be placed, and owing to the peculiar holding
character of india-rubber, sheets or plates of glass placed thereon will not be
moved by the processes of grinding and polishing the same, whether the glass
so treated be plate glass or sheet glass, and by such means the manufacture of
ground and polished plates or sheets of glass will be greatly improved.
The processes of grinding and polishing glass being well understood, it will
not be necessary for me to enter into any description of the machinery or
apparatus and materials used in those processes; and it will only be necessary
further to state that the surfaces of india-rubber used should be cut true on the
5 surface which is to receive the glass to be ground or polished. I use sheet
india-rubber, of about three-eighths of an inch thick, and of a size depending
on the size of the sheets or plates of glass to be ground or polished thereon,
and I place such sheets on to a bench or fixed surface of wood or other material,
but I do not confine myself to these details, so long as surfaces of india-rubber

page_text: are used for receiving sheets or plates of glass to be ground or polished, and
I have found that when the weather is cold and the surface of india-rubber
hardened thereby, that the surface should be slightly warmed before a fire or
otherwise.
I will now describe the fourth part of my Invention. In the manufacture
of crown glass it is well known that just before introducing the glass into the
flashing furnace, tho "nose" of the glass is heated at a furnace constructed
for that purpose, the opening out of such furnace where the nose of the glass
is applied being called by the workmen the nose hole, and such furnace is
commonly built in at one side of the flashing furnace. The air which causes
the rush of flame and heated vapours through the nose hole is introduced
below the fuel, by which means the draught through the "nose hole" carries
dust and prejudicial vapours into the glass, which is found materially to injure
the surfaces thereof. Now this part of my Invention consists in so constructing
this description of furnace that air may be introduced above the ignited fuel
in the furnace, by which much of the injurious effects of dust and prejudicial
vapours will be prevented coming through the "nose hole" of the furnace
when heating the "nose" of a glass which is about to be introduced into the
flashing furnace. The furnace employed is similar in all respects to those
now in use, with the addition of means of introducing air in a thin stream, or
in several streams above the ignited fuel in the furnace, and for this purpose
I construct on each side of the furnace a hollow space which opens into a
tunnel from the exterior of the glass house to admit atmospheric air, but
having dampers to regulate the air passing into such hollow spaces, and these
hollow spaces ascend and open into the furnace just above the fuel, so that
air will be admitted either in several streams or in one thin sheet of air inside
of the furnace, by which not only will the advantage above mentioned be
obtained, but a greater heat will result, which can be regulated with facility
by the dampers. I would remark that I am aware that air has been and is
introduced in various descriptions of furnaces above the ignited fuel therein.
I do not therefore claim such application of air to furnaces generally, but this
part of my Invention is confined to the so constructing furnaces of the descrip-
tion herein mentioned that air may be introduced above the fuel, whereby the
manufacture of crown glass will be materially improved.
Having thus described the nature of my Invention, and the best means I
am acquainted with for performing the same, I would have it understood that
I do not confine myself to the precise details, provided the peculiar character
my Invention be retained; but what I claim is,―
of
First, the improvement of the flattening kiln,
the application of a stone

page_text: capable of rotating horizontally, for successively receiving the cylinders of
glass to be flattened before they are moved on to the flattening stone.
Secondly, I claim the employing a flattening stone, perforated with
numerous holes, as herein described.
Thirdly, I claim the application of india-rubber for holding sheets or plates
of glass to be ground or polished, as above described.
And, fourthly, I claim the mode herein described of constructing furnaces
used for heating the "nose" of crown glass just before introducing the glass
into a flashing furnace.
In witness whereof, I, the said James Hartley, have hereunto set my hand
and seal, this Sixth day of January, One thousand eight hundred
and forty-four.
JAMES (L.S.) HARTLEY.
AND BE IT REMEMBERED, that on the Sixth day of January, in the
year of our Lord 1844, the aforesaid James Hartley came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and everything therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Enrolled the Sixth day of January, in the year of our Lord One thousand
eight hundred aud forty-four.