CERTAIN: IMPROVEMENTS IN THE MANUFACTURE OF, GLASS
Year: 1837

page_text: CLAY AND SMITH'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
NEALE CLAY, of West Bromwich, in the County of Stafford, Manufacturing
Chemist, and JOSEPH DENHAM SMITH, of, Saint Thomas's Hospital, in the
Borough of Southwark, Student in Chemistry, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Sixteenth day of November, in the first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
William Neale Clay and Joseph Denham Smith, Her especial licence, full.
power, sole privilege, and authority, that we, the said William.Neale Clay and
Joseph Denham Smith, our exors, admors, and assigns, or such others as we,
the said William Neale Clay and Joseph Denham Smith, our exors, adiñors..
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, our Invention of "CERTAIN: IMPROVEMENTS IN THE
MANUFACTURE OF, GLASS;"-in, which said Letters Patent is contained a proviso,
that we, the said William Neale Clay and Joseph Denham Smith, or one of
us, shall cause a particular description of the nature of our 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

page_text: by the same, reference being thereunto had, will more fully and at large
appear.
NOW KNOW YE, that in compliance with the said proviso, we, the said
William Neale Clay and Joseph Denham Smith, do hereby declare the
nature of our said Invention, and the manner in which the same is to be per-
formed, are fully described and ascertained in and by the following statement
thereof, that is to say :-
Our Invention consists in the application of certain materials in the manu-
facture of glass not heretofore so used, by which we are enabled to obtain
various descriptions of glass of an excellent quality and at a reduced cost, such
materials being used with the matters now employed or in substitution for
some of the matters now used in the various mixtures for making glass,
which is brought to market under various denominations, the names of such
glass depending in some respects on the process through which it passes, and
the uses to which it is applied; but all glass making may shortly be stated to
be the fusing of silica at a great heat with certain saline or alkaline substances,
and in some case the oxides of lead, at the same time there are probably no
two glass makers engaged in making glass which is sold by the same name,
who would agree as to the best mixtures to be used; and so far as our
experience goes we have not found any two makers, oither of flint glass, crown
glass, plate glass, or glass under other names, who employ the same quantities
of ingredients, and in some cases different makers vary the materials from
which the same named glass is manufactured; we are therefore unable to set
forth any general rule of glass making for any of the various named glasses; at
the same time, the materials which we apply to the purpose of improving the glass
manufacture in general will with greater or less advantages apply to the various
mixtures used by different glass manufacturers; we therefore propose to give
such mixtures of silex and the materials ordinarily in use, with such quantities
of the materials now to be newly applied occording to our Invention, as will be
suitable to the making of flint glass. The various processes of glass making
being well known to glass makers, no description will be required for per-
forming the same, such processes constituting no part of our Invention; nor
are the processes of fusing of the mixtures, nor the subsequent treatment of
the glass to produce the various named glasses, changed or altered; the
Invention relating to the application of certain materials not hitherto so used
in combination with silex and other matters for making glass.
And our Invention consists, first, in the application of combinations and
salts of barium, strontium, and zinc; and, secondly, in the application of
granitic or other rocks abounding with felspar.

page_text: In using combinations or salts of barium or of strontium, we prefer the
carbonates of barytes or strontia, which are found native in some parts of
this kingdom, or otherwise for them to be in the state of sulphate of barytes,
in which latter case we mix a proportion of charcoal or other carbonaceous
substances.
In using combinations or salts of zinc, we prefer the oxide of zinc, which
is formed during the process of manufacturing that metal.
Mixture for making glass by combining combinations or salts of barium
with silex and other materials:-Sand, 820 parts by weight; red lead, 150
parts by weight; carb. barytes, 145 parts by weight; carb. potash (pearl ash),"
112 parts by weight; nitre, 7 parts by weight; some little oxide of man-
ganesse, the usual quantity.
Mixture for making glass by combining combinations or salts of strontium
with silex and other materials:-Sand, 320 parts by weight; red lead, 150
parts by weight; carb. strontia, 108 parts by weight; carb. potash (pearl ash),
112 parts by weight; nitre, 7 parts by weight; oxide of manganese, as usual.
Mixture for making glass by combining compounds or salts of zinc with
silex and other matters:-Sand, 820 parts by weight; red lead, 150 parts by
weight; oxide of zinc, 56 parts by weight; pearl ash, 112 parts by weight;
nitre, 7 parts by weight; oxide of manganese, some little, as usual.
In some cases we do not use red lead (oxide of lead), but then we double
the quantities of carb. barytes, carb. strontia, and oxide of zinc respectively.
Other descriptions of glass we make with the following mixtures :-
Sand
480 parts by weight.

page_text: barytes
Charcoal -
Little manganese.
Sand
Chalk
Sulph. soda
"
barytes
Charcoal -
Little manganese.
-
parts by we
90
"
"
8
"
39
960 parts by weight.
-
200
"
"
-
290
"
"
->
460
"
"
40
"
1
Sand
-
960 parts by weight.
Chalk
-
200
"
Sulph. soda
-
290
"
"
strontia
-
370
"
"
13
=
40
"
"
12
Charcoal
Little manganese.
These mixtures form cheaper glasses, as they enable the manufacturer to use
ess alkaline or saline substances than before.
We will proceed to give mixtures of the application of these rocks in which
elspar predominates, and which, at the same time, contain very little or no
xide of iron, as, for instance, a mineral found in Cornwall, and used in the
otteries under the name of "Cornish stone;" this we use in conjunction
with common salt or muriate of potash, and we find these mixtures to afford
good and cheap glass.
Cornish stone powdered fine as sand 100 parts by weight

page_text: ourselves thereto, and the glass manufacturer will readily adapt our Invention
to the object he desires; for it will be seen that an important feature of our
Invention is in some cases to reduce the necessity of using so much red lead,
and in other cases to dispense with the use of red lead altogether, and in other
cases to reduce the extent of using alkaline or saline substances by the appli-
cations of other materials. Hence, suppossing a glass maker is about to
apply any of the substances herein mentioned as constituting our improve-
ments in the manufacture of glass, and supposing him to have a particular
mixture of his own, which, as before stated, is most generally the case, he
will apply some one or more of the matters herein mentioned, for it is not
necessary that only one of the matters should be employed in any particular
mixture.
And we would have it understood that wo lay no claim to the using of any
of the other materials herein described, nor do we confine ourselves thereto,
as there are other materials used in glass making for various purposes, and as
is well understood.
But what we claim as the first part of our Invention is, the application of
compounds or salts of barium, strontium, and zinc in combination with silica
or other materials, in the manufacture of glass.
And, secondly, we claim the application of granitic or other rocks in which
felspar predominates, in the manufacture of glass.
In witness whereof, I, the said Joseph Denham Smith, have hereunto set
my hand and seal, this Sixteenth day of May, in the year of our Lord
One thousand eight hundred and thirty-eight
J. DENHAM (L.s.) SMITH.
AND BE IT REMEMBERED, that on the Sixteenth day of May, in the
year of our Lord 1888, the aforesaid Joseph Denham Smith came before
our said Lady the Queen in Her Chancery, and acknowledged the Speci-
fication aforesaid, and all and every thing 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.
Inrolled the Sixteenth day of May, in the year of our Lord One
thousand eight hundred and thirty-eight.