CERTAIN METHODS OR PROCESSES FOR THE MANUFACTURE OF PLATE GLASS, AND ALSO OF SUBSTANCES IN IMITATION OF MARBLES, STONES, AGATES, AND OTHRE
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
Dop, of No. 12, Buckingham Street, Adelphi, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster, the Twelfth day of November, in the
fourth year of Her reign, did, for Herself, Her heirs and successors, give and
grant. unto me, the said Charles. Dod, my executors, adminstrators, and
assigns, Her especial licence, full power, sole privilege and authority, that I,
the said Charles Dod, my executors, administrators, and assigns, and every of
them, or such others as I, the said Charles Dod, my executors, administrators,
and assigns, should at any time agree with,, and no others, from time to
time and at all times thereafter during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within that part
of the United Kingdom of Great Britain and Ireland called England, the
Dominion of Wales, and Town' of Berwick-upon-Tweed, and also in all Her
Majesty's Colonies and Plantations abroad, in such manner as to me or them,
or any of them, should in my or their discretion seem meet, my Invention of
"CERTAIN METHODS OR PROCESSES FOR THE MANUFACTURE OF PLATE GLASS, AND
ALSO OF SUBSTANCES IN IMITATION OF MARBLES, STONES, AGATES, AND OTHRE.

page_text: MINERALS OF ALL FORMS AND DIMENSIONS, APPLICABLE TO OBJECTS BOTH OF USE
AND ORNAMENT;" in which said Letters Patent there is contained a proviso
obliging me, the said Charles Dod, by an instrument in writing under my
hand and seal, particularly to describe and ascertain the nature of my said
Invention, and in what manner the same is to be performed, and to cause 5
the same to be enrolled in Her Majesty's High Court of Chancery within
four calendar months next and immediately after the date of the said 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 1
Charles Dod, do hereby declare the nature of my said Invention to consist of
the following, that is to say :-
Certain new methods or processes for the manufacture of masses of colorless
or colored glass in at one and the same time, giving them the forms which
indicate their use, such as slabs, table tops, chimney pieces, vases, cups, 1
columns, in short, objects of all forms and dimensions, and whereby those
difficulties which have hitherto existed in casting or running glass direct from
the melting pot into moulds, giving the required forms, and which has been
attended with considerable expense, are avoided, since, by my simple and
economical methods and processes the same results can be obtained, with
variations of every kind; and also for the manufacture of colored glasses and
other vitrified substances, with veins, rays, or stratifications, and in imitation
both as to their colour, breaks, veins, rays, stratifications and dispositions of
marbles and stones of all kinds, jasper, agates, porphery, onyx, and lapis-
lazulli, and rivalling them in brilliancy and beauty. And I, the said
Charles Dod, do hereby also declare that the manner in which my said
Invention is to be performed is described and ascertained as follows, that is
to say :-
arrange
I take glass of any sort, in pieces of any sizes, and either colorless or colored;
and place it in moulds made of fire clay or refractory earth, the interior
surfaces of which I have done over half with white plaister of plaister of
Paris, and half with talk; which gives me very smooth surfaces; and I also
the pieces of glass according to the disposition of the design I wish to
form, if any. I place these moulds in a muffled furnace or oven, that is to
say, a 'furnace or oven similar to those used by painters. on glass, which are
disposed in such a manner as to contain the pane of glass hermetically sur-
rounded or muffled, so that the muffle receives the 'heat and transmits it to
the glass, which is melted after a certain time by this process. My moulds
being thus covered or muffled that they may not be exposed directly to the

page_text: flame but to the heat only, and that only across the mould and the muffle,
I gradually bring the heat of the furnace or oven to the temperature requisite
for a commencement of fusion, which I increase to a degree sufficient to solder
together all the parts or pieces of glass enclosed in the mould, so that they
become but one same and single piece. If I desire to make vases or columns
for instance, my moulds aro analogous to those used in metal foundries,
excepting only that my moulds are constructed of fire clay, as before stated.
I place above or over the moulds, funnels (or tunnels); made also of fire clay,
into which I pour glass in a somewhat more fusible state, and which in
melting fills into the cavities which remain between the pieces of glass
contained in the mould: In short, it is easy to perceive that by this operation
I can inaké in vitrified matter objects of all forms, sizes, and thicknesses.
With furnaces or ovens supporting a greater or less degree of heat (and which
depends upon their construction and materials) I-am enabled to unite thus
iuto ñiasses of all dimensions glasses of every description, and even 'miñerals
resulting froni à natüral fusion, such as basalt, &c. To succeed properly it is
essential that the heat received by the mould should be greater beneath thān
above, because if the air contained between the pieces united by the fusion
was envellopped by it would leave cavities or produce an ebüllitión; my
furnaces or ovens therefore are constructed upon the same principle as those
used by bakers, with the sole difference that mine are not heated by putting
the fire within but beneath; and it is also necessary, for the above reason, tō
produce that füsion slowly and by successive gradations. I also permit mỹ
furnaces or overs to grow gradually cool, after having hermetically closed
them, and I open them only after a lapse of some time, calculated according
to the sizes of the pieces contained, and which is sufficiently indicated by
practice, the object being to prevent any risk of breakage being incurred.
To employ these methods or processes for the formation of blocks and objects
of all dimensions in glass or other vitrifiable substances, either in imitation of
marbles and precious stones, or giving thein fine-imaginary effects, I have
sought what would be the means of obtaining, at a low price, opaque and
veined glasses of all colours, which I could put into form at will; and
iny researches lead me to apply to vitrification the principle of the oxidation
of-metals reduced by fusion in ordinary glass furnaces in the niass of glass;
to which I have been brought by the observations which chemists make upon
minerals in melting them by means of the blow-pipe. I have seen that a
globule of glass containing a metal was reduced to à state of transparency by
the fire called the fire of reduction, and that-in applying to the same globulė
the fire called the fire of oxidation the metal contained in the globule of glass,

page_text: where it had become more or less vitrified, took the, colour peculiar to its
oxide. I have sought what were the metals best calculated for these effects,
and I have only in this respect had to follow. the indications pointed out by
the chemists. I therefore apply a known principle to a new production;
for after having made glass in an ordinary glass-house furnace containing
metallic oxides susceptible of oxidation, by placing that glass in my moulds as 1
have herein-before explained, I make them undergo the oxidation appropriate
to them, and they then present the colours I desire, and which are all more or
Jess opaque at will. To instance one of the effects obtained by the application
of this principle, and to prove the power of colorization obtained by my
processes, I will observe, for example, that silver (one of those metals the effect
of, which are the most sensible or observable) reduced to the state of sulphur,
after having divided it by a dissolution and precipitation of any sort, calcined
with an equal quantity in weight of pulverized sulphur, will give, introduced
into a composition of flint glass in the proportion of one part in two, or even
three thousand, on removal from the glass pot, a transparent glass, and tinged
only with a clear yellow. This same glass, submitted to my fire of oxidation,
becomes opaque and of a whitish yellow throughout all its mass, there
remaining only a small portion of transparent glass, which, interposed between
that which has received the color, produces the most varied effects of stratifi-
cation. All objects thus manufactured should be polished as looking-glasses
are, and which gives them the most beautiful effects. The application of my
methods and processes, herein-before described, upon a large scale, will effect a
great saving in the manufacture of glass, and will also introduce new substances
in the manufacture of those objects of use and ornament to which at present
marble, stones, agates, and other minerals are almost exclusively devoted.
With reference to the furnaces or ovens which I employ, and which are
constructed similarly to those used by painters on glass, as herein-before
described, all modifications are good provided the glass receives the heat in
the manner herein-before described; the application of talk to prevent the
matter from adhering to the mould is merely an application, upon a large
scale, of the use made of it by manufacturers of cameos, artificial eyes, &c.
And whereas as regards the said Invention I claim the methods and
processes
as herein-before described for the several purposes to which they are severally
and respectively applicable, as herein-before mentioned; and such Invention, so
described, being, to the best of my knowledge and belief, entirely new and
never before used in that part of Her Majesty's United Kingdom of Great
Britain and Ireland called England, the Dominion of Wales, and Town of
Berwick upon-Tweed, or in any of Her Majesty's Colonies and Flantations

page_text: abroad, I do hereby declare this to be my Specification of the said Invention,
and that I do verily believe this my said Specification doth comply in all
respects, fully and without disguise, with the proviso in the said herein-before
in part recited Letters Patent contained; wherefore I do hereby claim to
maintain exclusive right and privilege to the said Invention.
In witness whereof, I, the said Charles Dod, have hereunto set my hand
thousand nicht hundred and
CHARLES (L.S) DOD.
AND BE IT REMEMBERED, that on the Twelfth day of March, in the
fourth year of the reign of Her Majesty Queen Victoria, the said Charles Dod
came before our said Lady the Queen in Her Chancery, and acknowledged the
Instrument aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Instrument aforesaid was stamped
according to the tenor of the Statute made in the fifty-fifth year of the reign
of His late Majesty King George the Third.